The Toil and Trouble Trilogy, Book Two — V.J. Chambers

Olivia Calabrese struggles to deal with the fact that her boyfriend Brice turns into a berserker-rage-filled monster-every night at midnight, and that if she ever has sex with him, she'll turn into one too. When she's not busy looking for a cure (that everyone claims doesn't exist) for the berserker virus, she's trying to deal with the threats her mob boss father Lucio levels against her newly formed jettatori "family."If that weren't enough, it's becoming clear that Tommy, her mentor and friend, is a double-agent for Lucio, feeding information to Lucio so that he can try to kill her with armies of berserkers. And to make matters even worse, her right-hand man Josh seems to be developing a crush on her, something that Brice is not particularly happy about.