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.