The seventh entry gets two stars not because I felt it was markedly worse than the previous entry, but because some of Forrest's tropes are becoming tiresome. The one that stands out the most is:
Characters with no development nor emotional connection to the reader get introduced, behave horribly off-page, and now Kate hates them.
Torie, Kate's former partner, after being only a telephone character in Book #5 that Kate appreciates, ghosts Kate for most of book #6 after (possibly) inadvertently shooting Kate causing Kate to no longer trust her. Now, despite apologizing at the very end of the book, in this book, she's become an incompetent detective who nearly screws up a murder case. This pattern is clearly repeating with Kate's heretofore unknown brother appearing at the end. Everything looks fine except (in-between this book and Book #8) once the brother finds out Kate is a lesbian he freaks out and I suspect and hope there is no coming back from that behavior.
Another one? Aimee being utterly annoying. In Book #5, a few chapters came from Aimee's point of view. However, that ceased with the past two books, and every appearance is Aimee complaining and nagging--and expecting preferential police treatment, demanding Kate abuse her police power.
So, it's not surprising that Kate makes out with another woman and narrowly avoids sleeping with her. Surely this will bring their relationship troubles to a head. Nope. She makes over-compensatory love to Aimee when she gets home, and Aimee is too dull to note the somewhat odd behavior. When Kate does abuse her police power (with the help of her new partner) to help a friend of Aimee, Aimee offers to return the favor. So, all Aimee cares about is getting what she wants. She nags and complains when everything isn't exactly as she wants and when she gets it, her brain shuts off. I really hope these two break up for good, so Kate's love-life can be interesting again.
Hey, what about the story? Well, it starts off with a chapter set during the Pleistocene epoch, 40,000 years ago--because a murder happens at La Brea Tar Pits in the present. Yes, the book has time for this. Later, Kate slips into a daydream as her fantasy lover/murder suspect gives a talk about her archaeological dig adventures. Naturally, this leads to the make-out session...
Kate berates herself for doing it in public (fair enough), but then gets upset and says, "She's a murder suspect! What are you doing!?" Um, Kate...in Books 1, 2, & 3--you did the same thing. You are living with--married to even--a woman you met the same way. Technically, they were more witnesses than suspects, but they hadn't been ruled out. In Book 1, it was the same day. In Book 3, it was Aimee, but it would also have been her aunt Paula if Kate had the chance.
As with earlier books, the "big issue" can't be resolved. In this case, it is because it is a real-life incident, the missing fossils of Peking Man. I suppose the Hiroshima connection was a nice little bow on it, but it felt like it was used so the author could lament the bombing itself rather than wrap up the story.