The HART Algorithm: A spicy slow burn STEM romance with nerdy banter and combustible chemistry

by Evita Wren

She controls the parameters.
He’s the extraneous variable.

Doctor Fia Hart has no time for emotional chaos. She didn’t just write the book on optimizing romantic compatibility, she built the algorithm and the world-renowned app to back it up.

Love distilled. No guesswork. No games.

So when charming, infuriating, heart-on-his-sleeve Professor Cade Aspen challenges her research—and bets he can make her fall in love with him before the semester is up, without touching her algorithm—Fia agrees.

If only to watch a hopeless romantic crash and burn.

But Cade quickly realizes he has no interest in proving her wrong. He doesn’t want to win the bet. He wants to win her.

Fia is brilliant, blunt, and sharp enough to leave a scar—but her walls are higher than the pile of rejected research proposals in the psych department faculty lounge.

He agreed to play by her rules, but what happens when he can’t resist breaking them?


From the author of the Edgewater series, The HART Algorithm is an opposites attract STEM romance with a guaranteed happily ever after and plenty of spice.
First in the HART series.
The HART Algorithm is intended for adults only. It contains potentially triggering material and explicit language. Triggers, tropes, and extra information can be found within, and on the author's website.

256 pages, Kindle Edition

Published September 30, 2025

About the author

Evita Wren is an indie romance author.
She writes heartfelt, spicy, and occasionally funny contemporary (for now!) romance designed to hurt your feelings a little before you get to that sweet HEA.
She enjoys crafting relatable and realistic emotional conflict, character-driven intimacy, and the odd suspense-adjacent twist here and there.
Evita’s favorite things to write are witty banter, well-earned spice after a good slow burn, emotionally resonant character arcs, and realistic bodies (you won’t find washboard abs here unless it fits a character’s lifestyle, which is almost never, sorry!).
She mostly writes MF contemporary, but also MM, FF, and MMF triad/poly relationships (throuples, if you don’t dislike the term like she does).
Her current project is the Edgewater Romance series, beginning with Harper's Landing!

Reviews

[Nikolett Ungor · Rating 5 out of 5]

Disclosure: I received an Advance Reader Copy (ARC) of this book in exchange for an honest review. As someone who loves supporting indie authors, I always aim to share thoughtful, fair feedback. While I have personal reading preferences like a love for fantasy, horses, or specific tropes, I never let that impact my rating unless it is relevant to the book’s intent or audience. I review with the genre and readership in mind.

Star rating: ⭐⭐⭐⭐⭐
Spice rating: 🌶️🌶️
Darkness/Bloodiness: -

Some tropes:
- Fall in love bet
- Banter
- Mature characters
- Academy setting (professors)
- Opposites
- Grumpy X Sunshine (reverse)

As a nerd I was captivated by the cover, it is so geeky and I love the characters' expressions on it. You can absolutely expect to see more of those lovely faces in the book and much more. If I met my fiancé in university, this would be us for sure, the hilarious banter and the picking on each other just reminded me so much of my own love story!

The plot is absolutely genius in my opinion, exploring love and how to use data to help love develop. I am entirely sure I would be Cade, representing the opposing side, how love cannot be analyzed to be simplified. The depth to the academic setting was great, I felt like I am back in uni both with the language and the environment.

You definitely have to expect lighthearted, romcom vibes from the book. I think I had a new annotation in my e-copy every 5 pages marking a hilarious line that made me laugh out loud. I am fairly sure my mother was concerned by all the laughing from my room. The romance is very sweet in the book, I found it incredibly realistic, developing slowly over time, not rushing into anything.

The side characters were really good, I already can't wait to see Grant get his own story, he definitely has a spot in my heart now and I want to see him get a Happy Ever After! I really badly loved the relationship of Neve and Fia (sisters), if I was close to any of my siblings I would absolutely want a relationship like that.

I think many people can relate to being compared to their sibling and having trouble with that, you will be happy to read how these two girls deal with that. If you enjoy realistic body representation you will love Cade even more, he is not a perfect all abs Greek god character, he has a soft belly and I love seeing body positivity in my books!

The conflict was not my cup of tea, but it was short enough to not take away the wonderful experience for me, I think other people will enjoy the conflict much more. I think I felt so deeply about the main characters since I saw my own relationship in them, I struggled to let them be characters (if that makes sense), but this special experience also made me want to purchase my own paperback copy to display it on my wedding! I am really struggling over here to put into words just how deeply this book affected me. I hope you will have just as much fun with this story as I did!

Let's do a quick summary. If you love the mentioned tropes, you need something really funny and sweet with moderate spice to read, then just dive head first into The HART Algorithm because I think you will love it too!

A quote from the book (You can't expect me to be able to choose a favorite, how dare you!):
"I think it's working," he says, his voice low and teasing. "I'm starting to feel unprofessional feelings for you, Doctor Hart."

[Nik · Rating 5 out of 5]

ARC received in exchange for an honest review. Thank you Evita and her team!

4.75/5 ⭐

“My prize is Fia Hart. My prize is Fia’s heart.” 

The HART Algorithm checked many boxes of stuff I like: women in STEM, academic romance, characters in their 30s, realistic bodies, grumpy/sunshine, sharp and witty banter, all the good things. And it delivered!

This book was a fun and surprisingly emotional read. What starts as a bet quickly turns into something so much deeper, and following along on that journey was beautiful.

The chemistry and immediate attraction between the main characters made for great back and forth snarkiness and teasing. 

I absolutely love a strong, soft around the edges male lead. He’s not Chris Hemsworth in Thor, which is incredibly unhealthy to sustain. He's got strength, and manly man arms, but he has a soft belly. It was really refreshing to see that in the romance genre when so many male leads are jacked to high heaven. Fia’s body also wasn't ever described as teeny tiny or having a flat stomach or whatever. She just is an adult woman with one type of an adult woman's body, and it's not made a big deal of. I loved that!

I have chronic migraine, and I really appreciate seeing migraine portrayed as horrible and day-ruining as it is. Fia takes care of Cade during a migraine attack he has, and it melted me. It's so emotional for me to see characters taking care of each other when the other is in pain, and just very healing for me. For these characters specifically, it was a turning point in their relationship for Fia, and her inner monologue about it was lovely. I swooned!!

The side characters were a hoot and so much fun. Cade's family is precious and hilarious and they should be protected at all costs.

The big conflict happens late in the book, and it thankfully does not last very long. It was just enough to break my heart without making me wait too long to put it back together.

One small thing I did not love is the persistent sexualization of Fia by Cade when they first meet, in a professional setting where she is presenting and taking questions. He stares at her “full round breasts” in her professional wear. He immediately thinks about how “fuckable” she is. In a way, it did fit somewhat with his characterization if you think about it deeper as he is doing research on natural sexual attraction and this kind of stereotypical male objectification of a woman sort of fits with that. Even with that context, I didn't like it very much and it almost turned me off the book, but Cade gets better quickly and is shown to be much more full of depth than originally portrayed, so this was just a little blip.

Overall, I thoroughly enjoyed this book and would love to read more by this author!

[Kate Laycoax · Rating 5 out of 5]

When I tell you I am obsessed with this book, I mean OBSESSED! Capital letters, underlined, highlighted, tattooed in my heart kind of obsessed. The Hart Algorithm by Evita Wren is one of those rare books that doesn’t just entertain you, it owns you. This book completely cracked my top 5 of all time, and I do not say that lightly.

First off, I had never read Evita Wren before receiving this ARC, and I cannot believe I almost missed out on her brilliance. This book is so flawlessly crafted that I immediately vowed to devour everything she has ever written (and will write). The way she combined STEM romance with raw emotional depth reminded me of Ali Hazelwood, but honestly, this feels even sharper, fresher, and more emotionally gripping. Yes, I know that’s a bold claim, but Evita Wren deserves it.

What drew me in instantly was the premise. It gave me the same spark I felt reading The Soulmate Equation by Christina Lauren, which is another favorite of mine. Both explore love through science, algorithms, and data, but Evita Wren takes it one step further by pitting science against spontaneous connection. Fia, the woman who built the love algorithm, doesn’t believe in messy, unpredictable chaos like real world romance. Enter Cade: a hopeless romantic who bets her that he can make her fall in love without any app, no equations... just him. And my God, did Cade deliver.

Because here’s the thing: Cade may have started with a bet, but from the first moment, his heart was already hers. He was down bad for Fia in the best possible way. The yearning, the pining, the small acts of care... it was so clear that Cade wasn’t just playing a game. He adored her, in every single part of her brilliance, sharp edges, and vulnerabilities. His love for Fia felt unshakably real, and that’s what set this book apart for me. Cade is, without question, the best book boyfriend I’ve ever read.

And Fia... oh, Fia. She reminded me so much of Dr. Brennan from Bones. People label her as cold, distant, and unfeeling, but really, she just needed someone to love her for who she truly is. Watching her slowly unravel those walls, not by changing who she is but by being loved exactly as she is, was incredibly moving. Their chemistry was perfection: sharp, witty banter, such amazing tension, and slow burn intimacy that felt more intoxicating than any insta love could ever be.

And let me just say, the spice? Goodness, it was so HOT and so worth the slow burn wait. I was giggling, kicking my feet, and absolutely glued to those pages. But what made it perfect was that it felt earned; it was tender and sweet while still being scorchingly passionate. And Cade? The MOUTH on that man. When he drops a “sweet girl”? Good God. I just about melted right into the page.

The realism in this book is another thing I can’t stop praising. Cade and Fia aren’t your basic rom com characters; they’re real. They have flaws, fears, histories, and they live in a world that doesn’t pause for romance. Even the caretaking moments, like when Fia supports Cade through a migraine, hit me so deeply. Chronic migraine representation in romance is rare, and to see it handled with tenderness and authenticity made me love this book even more!

And let’s not forget the supporting cast! Cade’s family added warmth and depth, and don’t even get me started on Grant and Neve. The chemistry between them practically leapt off the page, and if their book isn’t next, I may riot. A Grant King romance feels like my destiny.

This book gave me everything: a brilliant STEM FMC, a hot and hopelessly devoted MMC, witty banter, tension that made me want to scream into a pillow, emotional depth that had me tearing up, and a romance so grounded and real that it feels like it could exist off the page.

Evita Wren didn’t just write a love story, but a masterpiece. The Hart Algorithm isn’t just a new favorite, but the kind of book that will stay with me forever, the one I’ll push into the hands of every romance reader I know!

Thank you to Evita Wren for the eARC of this amazing book.

[Chasity7474📚❤️ · Rating 4 out of 5]

I loved Cade. I loved how he spoke to Fia, how he knew how to handle her emotions even if they weren’t the same as his. Fia I struggled with. She was so difficult. I expected it but I feel like most of the time it was too much of a push back. Their story was a slow burn (on her end) and I appreciated how the relationship developed slowly and how they got to know each other. Overall the story was well written and interesting.

[Adriana Szaboova · Rating 5 out of 5]

I devoured this book! Literally could not put it down!

She’s been called cold, calculating, sterile
He’s charismatic, peppy, and messy

They decide to test a theory and boy is it a fun ride! I was giggle like a school girl, laughing and the banter, and crying along. Awesome blend of stem and romance!

Thank you for allowing me to ARC read for you!

[chloe bolton · Rating 5 out of 5]

Wow this book was a amazing read I didn’t want to put it down! I could relate to the main character in so many ways. She’s made me want to look at life a bit differently. The story was well paced and kept you wanting to read more.

[Emma · Rating 5 out of 5]

A cute but emotionally deep romcom.

The HART Algorithm is a really well written book that hooked me from the beginning. The plot was a classic in terms of STEM romcom but I devoured it due to the depth of the writing. The whole premise of the algorithm is a really interesting idea and it was explained very well.

The characters' emotions and flaws are written and explored so well and they gave the characters so much personality that it was really easy to connect with them. The characters had real world problems and were not perfect, allowing them to feel like real people.

I really enjoyed the book and it's always a delight to see STEM in books, especially as someone who works in the industry.

Definitely a 5 star book.

ARC received for honest review.

[Lisa Kimbrell · Rating 4 out of 5]

ARC review:

Slow burn, enemies to lovers

Love this story of finding love outside of an algorithm and learning to listen and trust the process.

[Devika · Rating 4 out of 5]

The HART Algorithm is a romance novel by Evita Wren. This book is right up my lane with the promise of some scientists, a developing romance and plenty of spice. I was really looking forward diving into this story. What will this story bring to it's readers? How spicy will this story be?

This book is described as spicy, so I was expecting quite a lot of spice. However, there were only a few spicy scenes in the book. This was a bit of a dissapointment for me, so I feel like this book should be advertised as a slow burn romance.

Check out my full review on my blog Boekensteeg

[Alisha · Rating 5 out of 5]

Stop it this was so good, I just *deep breath* ok, let's get into it.
First, this author has the absolute best dedications, under both of their pen names. I always know it's going to be good by just how hard that dedication grabs me.

Dr. Fia Hart has developed an algorithm aimed at breaking down the science of love and compatibility. After publishing her research and launching a dating app Fia is propelled into the spotlight and not quite sure what to do with it all. When the opportunity to teach an extra credit class at a university for their Psych department pops up she jumps at the chance because teaching is more of a passion than doing stuffy interviews and being on camera. During her introduction seminar at the university Professor Cade Aspen, of the school's Psychology department, calls Fia's research into question, arguing that love is too spontaneous to ever to simplified to an algorithm. She disagrees and Cade comes up with an experiment to test which one of them is right. He bets he can get Fia to fall in love with him in 60 days. What's there to lose? After some fine tuning 60 days turns into one full semester for Cade to get Dr. Fia Hart to fall in love with him.

The banter between the two of them as early as chapter 4 had me giggling and ready to run through the story. I couldn't believe how immediate their chemistry was, even if Fia wanted to fight it every step of the way. Fia was such a relatable character for me. Every story I've read from this author leaves me feeling super vulnerable when it's over, but it's never been bad. You don't expect to see the ugly parts of yourself on full display in a book and then having someone just love every moment of it anyway. Being told by someone that's claimed to love you that you're too much and at the same time not enough will do the worst kind of things to your brain. Clawing your way back from that is so hard and I wish with everything in me that EVERYONE that knows what that's like finds a Cade. Finds the person that's willing to break through your defenses while also giving you all the broken pieces of themselves to show, to prove, that every single piece is deserving and worthy of love and care. "If she'll give me the chance to do so, I'll make sure she won't have to hide anymore. I'll make sure her emotions are safe with me. I'll make sure she is safe with me. " 🥺🥺🥺

Cade was purely amazing from start to finish. I wish all men were as emotionally mature and in tune as he is. He knew from the moment he saw her that it was never going to be about the bet and even when he messed up he only ever wanted to fix it. He acknowledged that he was the issue, that he caused the damage, and that he needed to do something to fix it. The way this man was a fiend for her. The way he could never get enough. The way he praised and cooed and worshiped the very sounds that escaped her, ahhhhhhh. Cade Aspen is Gomez Addams in a Psych professor font and you cannot change my mind. This man 🔥🔥🔥

I'm don't usually swoon so hard for a slow burn but I swear to god these two had me head over heels for HAND HOLDING! The first time they kiss I swear I yelled "YES OMG FINALLY!!!" It was absolutely beautiful the way it was built up for those two. When you're dealing with someone that is so emotionally guarded from having dealt with really crappy things in the past you can't rush things and Cade really respected that with Fia. Yes, he (playfully) pushed her boundaries multiple times but that's why they had the safe word and she never used it because from the moment she agreed to the bet she wanted it just as badly as he did 😍😍😍 Cade was the perfect counterweight that Fia needed to rebalance and re-center herself within the world and Fia was the guiding light that Cade needed to show him he'd never be alone.

But don't let the slow burn make you think it's not hot as hell, because it is SO hot 🥵 I am forever a sucker for good girl praise and Cade can praise in the best ways, hooohmygod. The spice doesn't kick in until the second half but it is wellllll worth the wait. Like I said, swooning for hand holding so just imagine how good it is when he slides home, again and again 🥵🥵🥵 His chair, the desk, her apartment, the shower?!?! 🥵 So good.

10 out of 10. I cannot recommend it enough. One semester to fall in love, what's there to lose? 🤭

[kreader33 · Rating 4 out of 5]

Love written in the stars
I loved the science and analytics. I like learning new words and expanding my vocabulary.
I think many of us can relate to the student struggle. (And yes girl, correct them all! You earned that doctor title. Use it!!!)
Fia Maeve Hart and Cade Aspen are at odds with one another on perception of love and on their research. They are complete opposites in every way.
Neve makes me laugh loudly and obnoxiously. She has such spirit and is so decisive. Her sister bond with Fi is absolutely tender. Can’t wait to see more of her!
I had to put this down and pick it back up a few times. I related so much to Fi and became so protective of her so fast, I didn’t take it well when Cade dismissed her work and only seemed interested in after meeting her in person. He relied on the physical science he knew to figure her out and read her intentions. I was offended and affronted on her behalf. I was hesitant about the bet too. Kudos to the author for being able to instill such strong feelings for a character right off the bat.
Cade acts like a fun charming man who is never serious, until it comes to consent. Then he is a no nonsense man. No is a complete sentence. Boundaries. Confirmation. Verbal affirmation. Impact over intent. Why matters.
It may start out as a research bet for Cade, but he wants her heart as his prize; not to take down her research based on preconceived notions as he initially thought.
My heart broke for the way the internet trolls treated Fi. It made me want to send me dozens of roses myself. “I’m not trying to prove you wrong. I’m defending my research because you are trying to prove me wrong.” The fact that she thinks she’s not built for love, pains me so.
Perfect book not just for psychology people, but for technology people too. The story reminded me of Charlie from the Numb3rs tv show. Not everyone is obsessed with love, communication isn’t always easy, and human connections take work for some.
I would have liked to have had the characters names on their pov chapters. Sometimes I would be a page or two into the new chapter before realizing whose pov I was reading from. I had to reread a couple of times to figure out who it was.
The HART Algorithm is an engineers dream! I think I agree with Fi. Her algorithm, and the thousands of sites similar available today, are tools, not replacements. It may not be for everyone, but it will be the push to start for some.
I love the blending of mythology and astrology. So many different disciplines showcased throughout.
Fia’s struggle between emotionally sterile and over sensitive had me bawling. I think women often feel caught between not enough or too much.
I was absolutely gutted by the final argument of the book. They both cut each other deeply out of pain. It hurt to read. It was soul wrenching and explosive pain.
Men, grab a pen and take notes on that epilogue. Way to go Cade!
I’m looking forward to Grant King getting his happily ever after. He deserves a kind partner in his life.
Can we get the recipes for Cade’s drinks please?! We could all use some fun time!

Suggested reading order to date:
1. The HART Algorithm
2. All I Want for Christmas is Two
3. The KING Review

I received an advance review copy for free, and I am leaving this review voluntarily.

[Kate · Rating 4 out of 5]

This was my first Evie Wren novel, and I really enjoyed it! Her characters are well-developed, realistic, and have the kind of natural dialogue and chemistry that makes you root for them from the start. HART Algorithm is a smart, academic-tinged romance with great banter, a fun premise, and two leads who feel like people you could actually know.

What I Loved:
I loved the concept of mixing academia with romance—it’s a “nerdy” take that gives the story a fresh, fun spin. Fia and Cade’s dynamic was so believable; their tension and banter had me smiling throughout. The writing flowed well, and once the story found its rhythm, I couldn’t put it down.

What I Didn’t Love:
The first 30% felt a little slow for my taste, though I understand why—it’s a true slow burn. Still, it took me a bit to fully connect with the pacing before the story clicked into place.

Rating:
4.5 out of 5 stars — A clever, heartfelt romance with sharp banter and strong characters that made me smile more than once.

Spice Level:
2.5 out of 5 peppers — Warm & Steamy. A few on-page moments, but nothing overly graphic. The focus stays on emotional connection and character growth rather than spice for spice’s sake.

Recommendation:
If you love rom-coms with quick wit, intelligent banter, and characters you could easily be friends with, HART Algorithm is worth adding to your TBR. It’s equal parts heart, humor, and heat.

One Compelling Sentence:
A slow-burning, nerdy romance that proves sometimes the smartest thing your heart can do is fall headfirst. 💻💘

I received an Advance Reader Copy (ARC) of this book in exchange for an honest review.

[Heather · Rating 5 out of 5]

I should probably start by admitting that after reading two other Evita Wren books I am now firmly a huge fan of her storytelling. That isn’t to say I can’t give a fair review of course. But I have no reason to pull my punches with this book. “The HART Algorithm” is such a wonderful read. Wren has the ability to write characters that feel REAL. They aren’t stereotypical romance types. Her characters feel so natural, with body issues and emotions and hangups. Fia and Cade are perfect examples. Both felt so real that it was easy to connect with them. And I absolutely adored how gone Cade was for Fia almost from the beginning. It wasn’t love at first sight, but it was an attraction he knew he couldn’t ignore. And I could completely relate to the issues both characters had, feeling as if they weren’t worthy and finding ways to shield themselves from what they thought would be inevitable rejection. They took the time to get to know one another deep down and acknowledged each other’s insecurities. Plus, the story was set in the world of academia and both Fia and Cade were smart, successful scientists. (Fia was arguably more successful and it never made Cade so much as blink. Sigh!) This book was fantastic all around and I absolutely recommend it. A beautiful story, engaging writing style and multi-dimensional characters. I definitely fell in love with “The HART Algorithm.” (And on a personal note, I really hope Wren will write a book or books featuring Grant and Neve, too!)

[Chapter Chirp (Jessica) · Rating 5 out of 5]

ARC Review-

The Hart Algorithm centers around Dr. Fia Hart, creator of the HART algorithm and HART app, an app that finds people find true love matches using her scientific algorithm. When Dr. Hart is set to teach a seminar at a college she is met by fellow scientist, tenured professor, and HART algorithm skeptic, Cade Aspen. There’s sizzling attraction from the first glance, but also competitive tension between the two that leads to a bet that Cade can make Fia fall in love with him in sixty days sans algorithm. First off, I love their competitive flirting, the back and forth banter adds an extra layer to their already tantalizing chemistry. Speaking of chemistry, theirs is undeniable from the start where it begins as a passionate slow-burn that turns very hot and heavy but also endearing. Both MCs have similarities but also a lot of differences giving them a bit of opposites attract feel. Cade is a handsome golden retriever MMC with wit and charm, whereas Fia is a bit closed off with a wall built around her heart, but she does have the beauty and the brains. This was my first ever STEM romance and I’m so happy because wow, what an introduction into the subgenre. This story was smart, funny, but also heartfelt and obviously very sexy. It kind of gave me How to Lose a guy in 10 days vibes in a way but with the addition of spice and intelligence/academia. I would recommend for anyone who fancies a smart romance with a good bit of tension, steam, and spice!

[ThatsSomeGoodSmut · Rating 5 out of 5]

The HART Algorithm completely pulled me in from the start. I'm a STEM girlie so the premise alone, science vs. spontaneous connection, was enough to make me curious, but it’s the characters and their dynamic that made me love it. Smart, funny, and heartfelt, The HART Algorithm is the kind of romance that sticks with you long after the last page. If you love academic rivals, witty banter, and a slow-burn romance that pays off beautifully, this one is a must-read.

Fia is sharp, brilliant, and not about to let anyone poke holes in her carefully constructed world. Cade, on the other hand, is all charm and unshakable optimism, the kind of man who can’t help but push every one of her buttons. Their bet sets the stage, but it’s the witty banter, the tension, and the slow unraveling of Fia’s defenses that kept me hooked. I found myself laughing out loud at some of their exchanges, then quietly swooning at the quieter, more vulnerable moments between them.

What really stood out to me was how real everything felt. These aren’t cardboard romcom characters, they’re people with flaws, insecurities, and baggage, and the story doesn’t shy away from showing that. I especially loved how Cade is portrayed: not a flawless Greek god, but a man with softness, patience, and an emotional maturity that made him one of the most endearing heroes I’ve read in a while.

Thank you to the author for an copy of this book.

[Em · Rating 5 out of 5]

📚✨ The HART Algorithm by Evita Wren
⭐️5/5 | 🌶️2/5

As someone who actually focuses most of my psychology research on hookup culture and the queer community, I knew right away this book was going to hit different—the FMC is literally researching in a similar field, and I felt instantly connected.

What I love about Evita Wren’s writing is how they weave health conditions into their stories with so much care and authenticity. It never feels like a side note—it’s part of the characters, and it makes the whole book feel that much more real and human.

And let me tell you, this book delivered. A STEM heroine who had me fully obsessed, a hot MMC who is hopelessly devoted in the best way, banter that made me want to scream into my pillow, emotional punches that had me tearing up, and a romance so grounded it honestly felt like it could exist right outside these pages.

The thing that stood out most to me though? How real the story felt. The characters aren’t perfect, and they aren’t trying to be. They’re messy, vulnerable, funny, complicated—and it made the whole romance hit even harder.

This was heartfelt, smart, and swoony in all the best ways. The HART Algorithm is absolutely going to be one I recommend to everyone when it releases. 💙

⚡ Reading mood: screaming-into-a-pillow invested + fully undone by STEM brilliance

[Angie · Rating 5 out of 5]

This one took me a minute to get into, too, with the use of scientific lingo. It wasn’t that it was difficult to understand; it was purely me. I needed to be in the headspace for the proper usage of the lingo. It was used just enough that it is purely believable that you are reading the story of a woman with her PhD and a man working towards his while working as a Professor. Fia has created an app to help people find people they are compatible with, and Cade doesn’t buy into it. What starts as a “bet” from him, saying he could get her to fall in love with him before the end of the semester, we see that Fia’s walls are hard and they are high. We watch as she fights her feelings for him, while he openly shows his. Several times, I was so giddy with their interactions, like giggling and feet kicking, giddy. Eventually, Fia starts to let her walls down around Cade; ultimately, their relationship hits a big speed bump. With their sisters talking some sense into both of them because of how they reacted, they find themselves working through it.
The spice was spicing...and we love hot nerds. I can’t wait to see what book 2 holds. Evita’s writing always brings my heart both joy and destruction in the best way. But she does always put it back together before the book ends. This was a fantastic read.

[Amanda · Rating 5 out of 5]

Fia and Cade.

The HART Algorithm is going to not only tickle spaces in your brain that you didn't know existed but challenge the thoughts and feelings on the precipice of relationships, dating, and love. This novel hits all the marks for active reading. Meaning you have to pay attention because there is a lot of jargon between these two. I call it brainy banter.

Fia and Cade have different views on how one gets to the point of 'loving' another person and how a relationship can thrive without being planned. Honestly, though some of the best memories between these two are not planned so, Cade may be right. Although, having planned events are also critical to a good establishment of a relationship.

This book deep dives into all of the things that come with a relationship. Communication is key, being honest, open, vulnerable and so many more elements which cannot be controlled.

With all that said, Evita does an amazing job of navigating Fia and Cade's relationship with such care and ALL THE FEELS FOLKS.

So, buckle in and be prepared for some conflict, some love, and some expressing of feelings.

Thank you to the author for an advance reader copy in exchange for an honest review.

[Carly Fay · Rating 5 out of 5]

Ok so I love Cade & Fia!

Doctor Fia Hart is the creator of the HART algorithm - a tried & tested compatibility & relationship app based on 4 main areas. Professor Cade Aspen has been studying love, compatibility & relationships for years. But when Fia lands a job guest lecturing at Cade’s university, he sets a challenge - can he make her fall in love with him without using any of the HART algorithm concepts. Fia is an emotionally guarded character, having been unlucky in love, & told she’s too much or not enough. Cade is sunshine personified, extroverted & wears his heart on his sleeve. Slowly but surely, he’s able to break down some of Fia’s barriers just enough to be let in & the results are positively combustible! But when Fia finds out Cade has lied to her, she says some things she’s not proud of. Can they both find their way back to each other? Can love conquer all?

I read this in a few hours - engrossed in the storyline, the characters & the persistence of Cade to win over the woman who stole his heart right from the start.

[Sabrina Mordini · Rating 4 out of 5]

Rating: ⭐⭐⭐⭐
spice: 🌶️🌶️

I loved how this story blends science and romance in such a clever, heartfelt way. The HART Algorithm takes the classic “love vs logic” theme and turns it into something both smart and deeply emotional.

Dr. Fia Hart is all about data, precision, and control—until Professor Cade Aspen challenges everything she believes in, including her own algorithm for love. What starts as a simple bet quickly turns into something much deeper, full of banter, tension, and unexpected vulnerability.

The chemistry between Fia and Cade is fantastic—snarky, teasing, and full of slow-burn energy that builds beautifully over time. The side characters are also wonderfully written, and I definitely wouldn’t mind seeing more of them in future books.

While there’s a touch of spice, this story really shines for its emotional depth and character growth. The HART Algorithm is a fun, charming, and surprisingly tender romance about letting go of control and taking a chance on something that can’t be measured.

[Tonika · Rating 5 out of 5]

Can love be boiled down into an algorithm?

The premise for a bet between professors, the one who created the Algorithm and one who believes an algorithm will never be the same as falling in love organically.

You have your drama, your heartwarming moments, the turmoil, and then the HEA ending.

The story is both perfection and hits really close to home in some situations but thats what I have come to expect from this wonderful author.

The way Evita is able to pull a person in and makes her characters so very relatable (at least to me).

Key points in no particular order:
- absolute consent
- university setting
- professors with PH.D’s
- height difference
- Slow burn
- Yearning and Longing
- Great Banter
- Tattooed MMC
- Spicy

[Keri · Rating 5 out of 5]

Frist I would like to say a huge thank you to Evita Wren for letting me be an ARC reader this book 🥰

From the get go it got me hooked, hearing how Fia didn't think she was deserving of love made me want to reach through my kindle and hug her (even though Fia would not of appreciate that 🤣)

This book was so good I forgot time as by the time I finished the book 6 hours had pasted and I hadn't even relized 😆

This book made me feel all the emotions.
I love how understanding Cade was with Fia's feelings and making sure she knew he wouldn't do anything with out Fia consent frist made me so happy to read 😍

If you are a lover of rom-com, reverse Grumpy/sunshine and he falls frist i recommend you read this book ❤️

[Pà · Rating 5 out of 5]

This book completely blew me away. Fia Hart, a brilliant STEM researcher, was smart, relatable, and so well-written, and Cade Aspen, her grumpy yet soft Psychology professor, was just chef’s kiss. From the first sparks of snarky banter to the slow burning romance, their chemistry was electric and deeply emotional. The story included realistic flaws, chronic migraine representation, and supportive side characters. The story balanced humor, tension, and tenderness perfectly. The romance felt earned, with Cade’s devotion and respect for Fia’s boundaries making every intimate moment hit hard. A truly 5 star STEM romance. Thank you so much to the author for giving me the opportunity to read the book in advance, I received this for free and I'm leaving an honest review.

[Rebecca Newman · Rating 5 out of 5]

🌟🌟🌟🌟🌟
Read as an ARC but will be adding to the physical bookshelf when the hardback copy is released!

From the get go Fia and Cade are end game whilst being so real and relatable you forget its a story! Whether you have even been told you're emotionally too much or emotionally closed off, this book will leave you with all the feels as it shows true romance is never perfect. Fia and Cade are both messy, vulnerable and absolutely lush in every way as they discover not only each other but themselves along the way in this STEM romance!
Also the crumbs left for Neve and Grant are delicious, so here is hoping they get their own HEA??

Again.. 🌟🌟🌟🌟🌟
Evita Wren you have stolen my Hart! 💫💕

[Chantelle · Rating 4 out of 5]

I was totally addicted to this book from the very first chapter. The reverse grumpy/sunshine dynamic between Fia and Cade was perfection, and the banter had me laughing out loud more than once. Their chemistry absolutely sizzled, making every interaction feel charged and unforgettable.

The writing was sharp, witty, and so engaging—it kept me hooked all the way through. I also loved how distinct and layered the characters were: Fia’s brilliance and blunt edges paired beautifully with Cade’s warmth and charm. Together, they made such a compelling and heart-melting match.

This book had romance: humor, heart, and sparks flying off the page. ✨

[Emmalee Longbottom · Rating 5 out of 5]

I was lucky enough to have been selected as an advance copy reader for this lovely book!

When I say that I could not put this book down, I am not lying! I was reading every spare second I had at work yesterday!

⭐️⭐️⭐️⭐️⭐️ read for sure!
🌶️🌶️ just the right amount of spice. These scenes were written so well. I often times get the ick with the word choices used in spicy scenes, but not this one! They were so lovely that I believe my husband will also enjoy this book without reading it 😉

I love Cade so much. He won with me too!

[Sarah Landis · Rating 5 out of 5]

Reverse grumpy x sunshine perfection!

Cade + Fia = chef’s kiss. Their chemistry leaps off the page, and the opposites-attract tension had me grinning, swooning, and refusing to put this book down (yes… I may have stayed up until almost 4 a.m. to finish it 😅).

The rivalry, the bet, the banter, the spice—it all came together so flawlessly. Cade’s heart-on-his-sleeve hopeless romantic energy vs. Fia’s sharp, guarded brilliance made every page sparkle. This one is a must for anyone who loves STEM romance, witty one-liners, and late-night-page-turning obsession.

[Lyndsey Miller · Rating 5 out of 5]

I read this book in one sitting!

I gobbled it up like I do chocolate. Unashamed and with no self control 🤣🤣. It is delicious! I love Doctor Hart and her closed up heart. She is just a delightful character to read about. Been hurt before and misunderstood through your her whole life.

Professor Cade is charming and driven and the perfect MMC for this book. He is challenging but also kind, loving and also open with his feelings. Fia is obsessed but is trying not to be!

Definitely a slight rivals to lovers on Fia’s part.

I loved this science romance.

[Megan Key-Holliday · Rating 5 out of 5]

This book beautifully outlines what can happen when two opposing sides allow themselves to be open to new ideas! Fia and Cade stand on two very different sides when it comes to how love is. I really enjoyed getting to see it all from a more scientific standpoints. This is a fun read that just might change how you look at love and relationships.

[Courtney Head · Rating 5 out of 5]

I received this as an ARC read.

I love the grumpy/sunshine trope especially in this book because the FMC is the grump while the MMC is a sweet cinnamon roll.

This is a story about love but the love is based on data to ensure better compatibility.

This is a romcom that had me literally laughing out loud.

I highly recommend this book!