With Joey Matthews still missing and the search for Joe Carroll escalating, the FBI brings in Nick Donovan to run lead on the case, much to Ryan and Parker's dismay. Meanwhile, a follower from the past meets up with Joe Carroll, and their plans have a life-threatening result.

With Weston still in the hospital, Ryan and Parker attempt to outsmart their new leader Nick as a way to continue their search. In a surprising move, Joe reaches out to Ryan to demand Claire's location and reveals that he will go to great lengths to lure her out of FBI custody. Meanwhile, followers from the past make a shocking return.

After discovering Claire's location, Joe sends two followers to capture her, but Ryan may be one step ahead. Meanwhile, Jacob struggles with recent decisions causing his reunion with Emma to be less than ideal. Also, a relationship from Ryan's past plays a significant role in his future.

Ryan and the FBI discover a follower who might be able to lead them to Joe Carroll's location. Agent Weston returns to the case but his run-in with the cult may have had a bigger impact on him than anyone originally thought. Meanwhile, Claire and Emma come face-to-face for the first time since Joey's kidnapping.

The Havenport Police Department is brought onto the case and Roderick's role as sheriff is called into question, which leads him to make a shocking decision that threatens the safety of Joey. Meanwhile, Ryan goes against the FBI, hoping to gain the trust of one of Joe's followers.

With only a few days before Joe Carroll's execution, Ryan and Mike shift their focus to a new threat. Meanwhile, after being approved to start work again, Max rejoins the task force and comes dangerously close to a deadly menace.

The FBI closes in on a suspect whom they believe to be the culprit behind the latest murders, but Ryan believes the killer is still out there, leading him to dig deeper into dangerous territory. Meanwhile, Joe undergoes evaluation in the days leading up to his execution and a new threat tries to cover his tracks.

After the latest shocking discovery, Ryan finds himself being tracked by the new illusive killer and a game of cat-and-mouse begins leading them both back to Joe Carroll, for different reasons. Meanwhile, Max and Mike look for a stolen clue and Mark makes a shocking decision.