Fair Game - Patricia Briggs

Fair Game is the third novel in the Alpha and Omega series. I recommend reading the first two novels in the series, and the novella in the On the Prowl anthology before reading this story.

Charles and Anna are husband and wife. They're also werewolves. When the strain of Charles' job as enforcer becomes a problem, he's asked to help with a serial killer investigation in Boston. The serial killer has murdered three werewolves so far, and that's something even the FBI could use a hand with. Charles and Anna are trying to reconnect on a personal level, while they also try to help the FBI. There are plenty of fae, witches, and werewolves, but humans can still be the most dangerous species to deal with. Very highly recommended.