One year after Joe Carroll's passing, Ryan Hardy has moved on with his life. However, events catch up to him when three men wearing Carroll masks stage a bloody subway slaughter. The FBI want Ryan to consult but he claims to have no interest in the new investigation. Meanwhile, some of the surviving Carrolites try to puzzle out who the newcomers are, and Mike tries to deal with the guilt of Debra's passing.

After the tragic subway huggings, Ryan's obsession with the case becomes stronger than ever. Soon, mysterious phone calls bring him face-to-face with what may be his biggest threat yet. Meanwhile, revelations surrounding Joe's new life are brought to the surface.

The FBI becomes more aware of Ryan's undercover agenda as he searches for a link between the tragedies in New York and the remaining members of the Havenport cult; a shocking event leads to Joe starting a new plan.

After the latest shocking revelation in the case, Ryan and Max attempt to put the pieces together and stay two-steps ahead of the FBI, despite Weston's constant warnings to stay out of the way. Meanwhile, Emma becomes even closer to Mark and Luke, while Joe and Mandy meet up with a follower in search of assistance.

In an attempt to learn new information, Ryan and Max capture a suspect. But complications lead to a game of dangerous cat and mouse. Also, Joe grows accustomed to his surroundings and establishes a plan of his own, while Emma realizes she is in dangerous company.

Concerned after Max narrowly escaped passing, Ryan calls Mike and asks him to bring in the FBI to capture Lily and her family. However, Mike comes alone and warns that there is a mole in the FBI tipping off Joe and his people. Meanwhile, Joe and Lily have a falling out.

Ryan and the FBI continue their hunt for Lily Gray, and are forced to redirect their search when a new threat enters Max's life. Meanwhile, Joe, Emma and Mandy arrive at their latest hideout, but quickly realize things aren't what they seem .

After a tragic turn of events, Ryan attempts to find the man who originally taught Joe tohug, in hopes of finding new answers. Meanwhile, at the compound, Joe tries to get his bearings, while Emma and Mandy wait for him to reveal his new plan.

Ryan, Max, and Mike draw close the spy within the FBI, but the suspect turns out to be someone they didn't expect. Meanwhile, Joe and Micah send Emma and two of Micah's followers out into the world to deliver Micah's message, a message that involves Carrie Cooke.

As his power over the Korban cult grows, Joe sets a deadly plan in action using new acolytes to carry out his demands. Meanwhile, Ryan and Max devise a plan to contact Joe, in hopes of tracking down his whereabouts, and Weston meets with a face from the past.

Joe's people launch a slaughter at a bakery, but Ryan soon realizes that they have an ulterior motive... and may not be connected to Joe. Meanwhile, Emma reinforces Robert's belief in Joe, Mandy makes contact with someone outside of Korban, and Claire demands to see Ryan.

After a series of public condemnations of Joe and his followers, Joe targets the son of a man who stands against him. Meanwhile, Ryan is faced with the shocking news of Claire's reappearance and Mandy makes a decision that leads her to a familiar face which could undo all that Joe has been working for.

Ryan tracks down the location of the Korban compound with hopes to infiltrate the cult and capture Joe Carroll, but all doesn't go exactly as planned. Meanwhile, Claire asks Carrie to deliver a message to Joe, and Weston makes a decision that will change the course of his life forever.

Joe Carroll puts his final plan into action, threatening the lives of many, as Ryan and Mike go to great lengths to stop him and prevent more innocent lives being lost. Meanwhile, Claire makes a decision that leads her into dangerous territory, and Mark and Luke attempt to figure out their next move.

Mark and Luke turn the tables on both Ryan Hardy and Joe Carroll, forcing the two sworn enemies to come together to save the woman they love.