Secrets in the Shadows is the second book in this series by Jenna Black, and it makes a number of references to events and characters from the first book, Watchers In The Night. Still, it isn't necessary to have read that book to understand the events of this story, focusing this time on Hannah, the feisty private eye, and Jules, the Quebecois vampire.
In Jenna Black's vampire world, humans aren't aware of the vampires (aside from a few special cases), and the vampires themselves are ranged against each other. Almost all vampires are Killers - those who drain humans for blood - and this feeding gives them significant power. Others, though, are members of the Guardians, led by Eli, who don't take human blood and who work as a kind of police force in Philadelphia, disposing of Killers when they can.
Jules is a vampire with a temper. Although he is the oldest of the Guardians (apart from Eli), he doesn’t display very good control over his emotions. When he discovers that the vampire who turned him, Ian, is on a killing spree in Baltimore, he goes to the Guardians for help in finding and finishing Ian. Eli isn't going to allow him - or any of the other Guardians - to step outside of their Philadelphia territory, so Jules decides to go it alone.
He's not quite alone, though. The mortal fiancée of Gray, another Guardian, hires Hannah to work with Jules and to protect him. Underneath Hannah’s is a tomboyish, mouthy, bold exterior hides a fear of being overpowered. Despite Jules's reservations, they work together to try to locate Ian and deal with him.
Unfortunately, it's far from easy. Ian, being a Killer, has far more power than Jules. They soon discover they have stumbled into some significant vampire politics, leading them to question Eli’s morals and ethics. They have to compromise some of their rules in order to get the job done and are continually in a position of danger and weakness as their opponents are older and stronger.
Although I enjoyed reading this book in some ways, the characterization feels rather lightweight. We don't really see much character development, and it is difficult to really get into the heads of Hannah and Jules. The story has several narrators, which serves to give a good all-round view of events, but it also makes it hard to know whom we should be supporting. Perhaps that is part of the idea of the book - to show that bad characters have some redeeming features and that good characters can do bad things to get results - but I found it a slightly awkward way of reading as my ideas of the characters seemed to have to change almost every page. I'm still not entirely sure at the end about Gabriel.
The romance aspect is also a little problematic, seeming to develop more for reasons of proximity than anything else and really being a side-issue to the main plot of vampire hunting. While the book makes a rather sluggish start, it does pick up toward the end where it becomes more enjoyable with tense situations for our hero and heroine. Overall a reasonable read but nothing special.