Two stars is supposed to mean "it was okay," but I use it also when there's a balance between what I liked and what I disliked, as here. This is a very dark urban fantasy. There's a high degree of gore and violence from beginning to end--imagine the climactic scene of a horror novel being repeated again and again without the creepy slow build-up typical of the horror genre. This story pulls you right into it and doesn't let you go till it's over. Big trigger warning, especially for the savagery that's perpetrated more than once on the first-person narrator, Dr. Carrie Ames.
This book is all about vampires, and some of the ideas in it were delightful. For one thing, all vampires have two hearts. A human heart is insufficient for the workload of a vampire's body, with that strength and speed, so when a human is turned, the body grows a new heart, bigger and stronger than the old one, which is kind of pushed into the background (of the rib cage). And even though the old human heart is no longer needed, it's the one that kills the vampire when it's staked--not the new vampire heart!
And the old human heart can be removed and stored in a box (this happens more than once in the novel), and it's still the case that if that heart is destroyed (staked), the vampire dies in flames, and at any distance.
As in other vampire stories, a person is turned into a vampire by a blood exchange, but once that happens, although that person is irrevocably a vampire from then on, there is a period of "turning" (see title) that takes a month or so before the full vampire nature manifests. Time to grow that new heart, maybe? Anyhow, once the body is ready, a triggering experience suddenly awakens the blood hunger and sensitivity to the sun, etc.
That sensitivity is at the extreme end of the vampire genre--exposure to sunlight causes something like third-degree burns, just like fire, and the vampire has only seconds to avoid death. Rapid healing, super strength, and an erotic desire for fresh human blood are as expected. More intense than in many other vampire novels is the effect of the "blood tie" (see series title) between sire and fledgling. It's a powerful emotional bond, with more than telepathy, as blood can be used to project the mind into the other's past experiences as though they were real in the present. (Much of the violence and gore in the novel comes along that route.)
The story is well written, quite readable, and scenes are easy to visualize--all too easy if you don't want to look at the details of people being torn apart and devoured by hungry vampires. Cyrus, the evil master vampire (600 year old), throws parties for other vampires in his mansion where homeless teenagers are rounded up and hunted down by the guests in an old-fashioned maze next to the house. The butler hauls off the corpses, or what's left of them. These vamps don't suck neatly, they devour chunks of their victims till they're satiated.
Cyrus is the "monster who sired" narrator Carrie Ames that night in the hospital morgue, by attacking her in just that fashion till she too was a corpse. But in his hungry carelessness, he dripped a bit of his own blood into her wounds, and she came back to life for a long convalescence in the same hospital. A month later, remarkably healed from her injuries and almost ready to return to work, Carrie discovers the hard way what the sun does to her. Eight months after getting her M.D. she has to resign--there's no way she can arrange for nights only and skip all meetings!
Carrie makes contact with Nathan Grant, a Scottish vampire who's a little out of place there in "mid-Michigan," and his teenage protege/ward Ziggy, who immediately attacks Carrie with an axe. And Ziggy is the most sympathetic character in the book. Nathan represents the worldwide Movement (full name Voluntary Vampire Extinction Movement), headquartered in Spain with a fleet of special jets that shield traveling vampires from the sun. The Movement is composed of vampires who kill non-member vampires with the idea that, once the members are the only vampires left, they will commit suicide to free the world of their evil. Possibly the most unusual and most head-shaking element of this book!
Anyhow, Nathan (the good guy who would be the hero if this were a romance) gives Carrie the vampire manual (called Sanguinarius) and an ultimatum. She has two weeks to apply for membership in the Movement or she will be on their kill list. He assures her that he only kills vampires when he gets a written assassination order from the Movement. If and when an order comes through for her, he will quickly kill her. He's the good guy, remember. If she's accepted into the Movement, she will have to follow the strict rules that govern Nathan, including carrying out orders to kill.
But her blood tie draws her inexorably to Cyrus, and she's caught between the two of them. Carrie goes one way and the other, feeling both revulsion and delight at Cyrus's carnage, feeling strong attraction to both Cyrus and Nathan, and sunk in a welter of emotion that overcomes reason again and again. She does many stupid things, takes impossible risks, and simply never has a clear head. On top of that she has to deal with Dahlia, a witch in Cyrus's retinue who keeps trying to kill her to prevent Cyrus from making her his queen.
The novel might have worked better with close third-person narration to provide an authorial voice distinct from Carrie's. All the characters are too heavily invested emotionally in one another to tell a story effectively, and that's true of Carrie especially. Her new heart is all over the place, and her account is quite overheated--it could be a soap opera except for all the blood and gore. And vampire life.