A group of suspects with a pack mentality who kill for the thrill of it are the subjects of a BAU manhunt.
Crowley notices Dean's increasing level of aggression; a vengeful man named Cole captures and tortures Sam.
A lieutenant's mummified remains turn up nearly 10 years after he was reported missing along with $1 million from his ship's safe.
Maura meets a man in an unusual way; Jane has mixed emotions when someone from her past returns.
The detectives must solve the 20-year-old case of a 6-year-old boy's rape and murder.