12 cold cases. 12 kidnapped women. One diabolical serial killer. In this riveting suspense thriller, a brilliant FBI agent faces a deadly challenge: decipher the mystery before each one is murdered.

FBI Special Agent Maya Gray, 39, has seen it all. She's one of BAU's rising stars and the go-to agent for hard-to-crack serial cases. When she receives a handwritten postcard promising to release 12 kidnapped women if she will solve 12 cold cases, she assumes it's a hoax.

Until the note mentions that, among the captives, is her missing sister.

Maya, shaken, is forced to take it seriously. The cases she's up against are some of the most difficult the FBI has ever seen. But the terms of his game are simple: If Maya solves a case, he will release one of the girls.