Over the last 10 years in Brampton, Maine, 28-year-old Carrie Lawrence, the narrator of Murphy's unsettling, blackly humorous debut, has reluctantly helped her serial killer sister, 30-year-old Becca, bury 12 bodies. Sociopath Becca, who has been a serial killer since her teens, keeps Carrie in line by saying she has planted DNA on each of her victims that will implicate Carrie. Life hasn't been great for Carrie, who both loves and fears her sister, but at least she knows her enemy. Then the police unearth a dozen bodies in a Brampton park, each missing a foot, and the sisters realize there's another serial killer in town, whom the press dubs Footloose. Becca and Carrie wind up matching wits with Footloose, who has his eye on the sisters, in a deadly contest that Becca thinks is fun but terrifies Carrie. Who will survive remains far from clear as the action builds to a series of unexpected twists. Murphy sensitively explores the bonds of sisterhood amid all the murder and mayhem. Those looking for an offbeat serial killer thriller will have fun. Agent: Jill Marr, Sandra Dijkstra Literary. (July)