Two killers are prowling Manhattan. It's double duty for Erin and Rolf.

A detective doesn't always have the luxury of giving all her attention to just one case. Erin O'Reilly and her K-9 partner, Rolf, have just started to sink their teeth into their latest investigation—a pair of Scottish gangsters, tortured, executed, and washed up on the rocks—when another mystery intrudes. A beautiful young woman is found dead in a locked hotel room, posed with a bouquet of fresh roses. It looks like a carefully staged suicide, but Erin isn't so sure. Soon she's juggling two cases at once, dodging bullets in a budding mob war while trying to nail down a cunning serial killer—one who just might be stalking her in return.