Cassel Sharpe was raised in the Curse Workers's world, where everyone is a con artist and every choice is a potential trap. His mother can emotionally control him, his brother can manipulate his memories, his ex-girlfriend is now part of the mob and he himself has a power so rare that its nearly mythical. He wants to get a high class education and win himself free of all the plots, but instead he keeps getting pulled deeper. The world building remains awesome. There are workers and non-workers. Workers can enact magic with a touch, but experience blowback if they do. For example, emotion workers can manipulate other people's feelings, but in return their own emotions become unstable. Or there are death workers, who can kill someone with a touch, but in return a part of their body dies--a tooth if they're lucky, their heart if they're not. Even healing has blowback of its own: by healing others, one becomes sick oneself. Working magic is dangerous and not to be done lightly. But for all that, it's so powerful that it's still used. And because all the magic is touch-based, everyone wears gloves constantly, and seeing someone's ungloved hand is both incredibly intimate and a little scary.
Cassel, and all the supporting characters, are equally well-thought out, well-rounded creations. And the plot is as twisty as ever, though not quite so mind-blowing as the first two books. I really loved this series, but I think Black was smart to end (or at least pause) it here. Cassel quitting school, the FBI, and all pretences of normality in order to have a little time with Lila was an incredibly gutsy plot twist, the equivalent of having Harry Potter quit Hogwarts in, say, the fifth book. It was smart, it was unexpected, and it completely shook up the books' loose formula. In all three books, Cassel has to juggle school, curse working, and the law--after the last chapter, the juggling act is over.