When a massive explosion at a top-secret prison known as the Pit allows notorious serial killer Richard Harris to escape, disgraced FBI agent Bex Henderson is called back into action to hunt him down before he kills again.

Clayton Jessup, a deranged serial killer who targets happy families, is on the loose and looking to kill again. The team must race against time to stop him before it's too late. Bex learns who she can and can't trust.

In rural Montana, the team hunts down Lowe, a brutal serial killer obsessed with wolves. Bex and the team must track Lowe through the wilderness while dealing with local Rangers.

When Bex and the team race to stop Roy Barber, known as the Couples Killer, before he strikes again, they uncover a chilling scheme that puts Roy's crimes in an entirely new light.

Bex and the team track the brilliant and beguiling Jenna Wells, the notorious Killer Chemist whose therapy in the Pit has made her even more dangerous and deranged.