The show catches up with a healthy and healed Ryan Hardy a year after the tragic events of last season. Following a horrific new murder spree, the FBI calls on Ryan and Mike Weston to speak with the lone survivor, Lily Gray, in order to help them solve the case. Having worked tirelessly to rehabilitate his life, Ryan is reluctant to re-engage with the FBI. Instead, he proceeds with his own investigation behind closed doors, and finds a valuable ally in his niece, Max Hardy, an NYPD cop working in the Intel Division. Throughout the season, Ryan will cross paths with several complicated individuals, including Mandy Lang and the enigmatic Luke, which furthers his suspicion that Joe Carroll's reign of terror is far from over.

When notorious serial killer Joe Carroll escapes from death row and embarks on a new killing spree, the FBI calls former agent Ryan Hardy, a psychologically scarred veteran who captured Carroll nine years earlier. Knowing Carroll better than anyone and close with Carroll's ex-wife, Claire, Hardy works closely with an FBI team, which includes no-nonsense agent Jennifer Mason and sharp upstart Mike Weston, and soon discovers that Carroll was not only communicating with a network of killers in the outside world, but has much more planned than just a prison escape -- and there's no telling how many additional killers are out there. As Hardy and the FBI team are challenged by the ever-growing web of murder around them, masterminded by the diabolical Carroll, Hardy will not only get a second chance to capture Carroll, but another shot at redemption, as he's faced with not one but an entire cult of serial killers.