Ryan and Joe must join forces to stop Mark and Luke from killing Claire as revenge for the death of their mother.
Joe launches his master plan and Mike and Ryan try to stop him. Meanwhile, Claire must make a decision, and Luke and Mark have to decide what to do next.
While Ryan tries to infiltrate the Korban compound, Mike makes a life-changing decision and Claire asks Carrie to give Joe a message from her.
Joe targets an enemy's son after being publicly condemned. Elsewhere, Ryan learns that Claire is alive, and Mandy makes a decision that could undo all of Joe's work.
While Ryan and Mike track down a new cult of killers, Joe continues training the Korban community in his unique plan to unleash a wave of terror and death.
Joe uses his new acolytes to launch a wave of terror to announce his return. Meanwhile, Mike meets an old friend while Ryan and Max use Strauss to try and make contact with Joe.moreless
While Ryan, Max, and Mike pursue the FBI mole with Director Franklin's support, Joe announces his resurrection to the world.
While Ryan tries to track down Joe's mentor, Joe, Emma, and Mandy start adapting to their new life at the compound.
While Ryan continues working with the FBI to find Joe and Lily, a new danger targets Max. Meanwhile, Joe, Emma, and Mandy arrive at the Korban Compound seeking refuge.
Ryan and Max call in the FBI when they find out where Lily and her "family" are staying. However, Mike has his own plan for taking on the killers. Meanwhile, Joe tries to cope with his new working arrangement with Lily, and Luke deals with the aftermath of Giselle's stabbing.moreless
Ryan and Max capture a suspect and try to learn where Lily and her group are, but things take a turn for a worse. Meanwhile, Emma blames Joe for leaving her in the lurch, while Luke and Jamel go to bring Giselle to the manor.moreless
Ryan and Max ignore Mike's warnings and continue their private investigation. Meanwhile, Joe and Mandy meet a new follower, and Mark and Luke draw Emma further into their web.
The FBI begins to suspect that Ryan isn't as out of the loop as he claims when they discover that he's been investigating Emma and the remaining Havenport cult members. Meanwhile, Joe is forced to go to a new plan.moreless
Ryan receives a call from two of the subway killers, who begin a deadly game with him. Meanwhile, Joe's cover identity is at risk when a local reverend realizes who he is.
One year after Joe Carroll's death, Ryan is trying to adjust to going back to his ordinary life. However, a new series of killings raises the question of whether Joe is actually dead or if his legacy has lived on.moreless
Megan and Tommy attend her father's exhumation but it only yields more questions. Joan suggests Megan check out her father's patient files for a connection to his death.
An accused murder violently escapes from a transport van and soon the witness in his case is found dead. He heads straight to Megan pleading that he's being framed and didn't commit the murder. It's up to Megan to find the truth.moreless
A plane crash in Philadelphia takes out the city's main power grid making it difficult for Megan and the rest of the team to conduct the necessary autopsies. While investigating the plane crash, Tommy and Riley are involved in a serious car accident.moreless
Megan and Tommy must determine who killed a schizophrenic teenage girl at a mental institution. To make things interesting, a patient claims that the murderer really meant to kill her, and they are being stymied by the ward director.moreless
An investment banker on trial for defrauding investors is kidnapped leaving court and later surfaces in a video as having been killed. Tommy and Adam have to determine if he faked his own death. Megan learns more about her father.moreless
When Tommy is discovered at the scene of a young girl's murder, covered in blood, Megan is his only hope.
A woman's savage murder leads Megan and Tommy to a neighbor inflicted with rabies who bites Tommy and is diagnosed with rabies. Kate calls in the new health commissioner, Dr. Charles Stafford, to help Megan when a second case of rabies is discovered sans bite marks.moreless
Kate begins to suspect that the handsome and mysterious Sergei, with whom she's having a tryst, may be involved in the death of a young Russian girl.
Working with Tommy on a vigilante killing, Megan meets up with a grief counselor who offers to help her deal with issues about her father's suicide.
The shooting death of a New York mobster's son creates a tense situation when the mobster threatens to find and kill the person responsible. Megan and the team must hurry to solve the case after one suspect is killed.moreless
Megan and Tommy must separate out fact from fiction to determine if a child's murder was severe child abuse or something else.
While Kate comes under fire from D.A. Russell, Megan has cracked the case but can't tell her team. As long as the killer has Lacey, Megan must keep what she's learned to herself.moreless
As Megan returns to work months after Peter's death, she is thrown together on a new case with a detective from her past. A serial killer is seeking out young war veterans but the case hits close to home for Megan when the killer takes Lacey hostage.moreless
Beckett is on the hunt for the man who shot her which puts Castle in a precarious position. Soon everything will be out in the open and nothing will be the same for the 12th Precinct.moreless
The only witness to a murder victim with human bite marks on his body insists it was a Zombie attack. Castle, Beckett and the rest of team must delve into New York's Zombie subculture to find the killer.moreless