At the Observatory, Mokrani and Catherine clash over the fate to be reserved for Micah, whom Catherine considers to be a major source of information. Micah reveals to Catherine that she has to find Bill Ward. The latter, for his part, tries to find out more about Emily, still assailed by visions of Adina, the leader of the aliens urging him to kill Bill.

Without telling Emily or her parents anything, Bill decides with Zoe to test on Emily the biological weapon he hopes to be able to use against the aliens. Catherine, for her part, has had difficulty managing her grief since Mokrani's death. She now has only one thing on her mind: to find out who Bill Ward is and find him. Sophia is ready to help him, but Nathan hesitates.

Catherine, Sophia and Nathan make their way to London, accompanied by Victor, a survivor encountered by chance. Along the way, the dangers multiply. Sacha's feelings towards Emily intensify and the young man's behavior becomes more and more disturbing. Feeling threatened, Bill is forced to flee.

Oh no! The Red Goobler's back and this time he's jacked! This one's too scary for me.

Jodie's celebrity is on the rise and M.O.D.O.K. plans on winning her back from her new boyfriend, the superhero Wonder Man. Jodie and her publicist invite M.O.D.O.K. to a party, knowing his temper will bring publicity. M.O.D.O.K. provokes Wonder Man into attacking him at the party and is kicked out. Wonder Man leaves Jodie when he sees she’s only using him for exposure. Melissa and Lou bond over their disappointment in their parents. M.O.D.O.K. and Jodie have sex when he goes to apologize, and it is revealed who exactly was behind her publicist’s actions.

A deadly face-off leads to a life-threatening moment; Catherine and Sam seek help for his parents.

Bill's latest discovery is put in jeopardy, even as trouble brews with the human aliens; Catherine must decide where her loyalties lie.

When two guards at a privatized maximum security prison in Texas are murdered, the BAU suspects that more than one UnSub within the prison could be at work.

Mysteries abound when pallbearers at a funeral lose control of a surprisingly heavy casket only to have a second unknown woman tumble out along with the original deceased.

The BAU is called to Wisconsin in search of a serial killer, and the team looks for a connection among the victims for clues to the UnSub. Also, Kate has trouble dealing with her niece, Meg, when she begins acting out.

When a beautiful woman is found dead in an alley, all clues point to her being a victim of the notorious Triple Killer. The Triple Killer, or 3XK, terrorized New York City four years ago, then mysteriously disappeared. Now he's back.

When Colter suddenly disappears during his search for a missing father, Reenie recruits his brother, Russell (Jensen Ackles), for help.

The 126 race to save a man crushed under a vending machine. While struggling to handle his aggressive foster horse, Owen finally faces the truth of his brother’s death. As Mateo and Nancy scramble to delete a nude photo of her accidentally sent to the 126, Tommy is concerned that Nancy may be facing a possible health scare.

On Brennan and Booth's first official day back at their respective positions at the Jeffersonian and the FBI, things get exciting when remains are found at a fish farm under suspicious conditions, prompting them to investigate. After it's discovered that someone harvested several of the victim's internal organs before he was dumped in the water, Angela tracks down the seller and buyer of the organs to try to uncover important details in the case. Meanwhile, Booth readjusts to his position back at the FBI and discovers Aubrey has taken over his old office; Hodgins pushes Angela to showcase her photography work; and Cam struggles with her decision to choose work over her relationship with Arastoo.

When two guards at a privatized maximum security prison in Texas are murdered, the BAU suspects that more than one UnSub within the prison could be at work.

The BAU is called to Wisconsin in search of a serial killer, and the team looks for a connection among the victims for clues to the UnSub. Also, Kate has trouble dealing with her niece, Meg, when she begins acting out.

While stalling the river bones investigation, Harrow digs into the case of a woman murdered with a crossbow, coming dangerously close to a thrill-kill murderer.

When Colter suddenly disappears during his search for a missing father, Reenie recruits his brother, Russell (Jensen Ackles), for help.

Responding to an "Officer Down" emergency call, Castle and Beckett's latest case takes a shocking turn when it's revealed that the victim isn't a cop but a male stripper dressed up as one.

When remains of real estate agent Justin Ross are found in the forest and appear to have been destroyed by coyote-wolf hybrids, Brennan enlists the help of fellow brilliant forensic anthropologist Dr. Beth Mayer (guest star Betty White) to assist in the investigation. In addition to her professional achievements, Mayer is surprisingly knowledgeable about the world of fantasy football, a key link to Ross' past and one that could provide vital information in finding his killer. As Booth and Aubrey dig into Ross' fantasy football league history, they discover he was actively involved in a Twitter feud with NFL star Lou Divers (guest star Ronde Barber), and was also owed a large sum of money from the league's commissioner, making each of them suspects. Meanwhile, Brennan resists feeling competitive as Mayer impresses the team with her expertise and decades of accomplishments.

While investigating the murder of a NYC subway worker found shot to death in Central Park, Castle and Beckett unexpectedly uncover the shocking and violent abduction of a young boy.

A gang killing leads Carlos to new information on his father’s murder. TK contemplates a major life decision as Owen is determined to get Austin’s first responders’ health care coverages increased.

When the wife of an increasingly prominent Congressman disappears, the BAU investigate and come to consider his adversaries and political enemies as potential suspects of the abduction, or possibly murder.

When an innocent family of four is abducted while vacationing in Barbados, Hotch and Cruz enlist the assistance of the FBI's most elite team in handling international cases. They realize that this situation closely resembles a case that the BAU once handled in Florida.

A human arm in a dead crocodile leads Harrow and Dass to Far North Queensland, battling crocs and crooks in their pursuit of the truth.

When a beautiful woman is found dead in an alley, all clues point to her being a victim of the notorious Triple Killer. The Triple Killer, or 3XK, terrorized New York City four years ago, then mysteriously disappeared. Now he's back.

While investigating the murder of a NYC subway worker found shot to death in Central Park, Castle and Beckett unexpectedly uncover the shocking and violent abduction of a young boy.

Responding to an "Officer Down" emergency call, Castle and Beckett's latest case takes a shocking turn when it's revealed that the victim isn't a cop but a male stripper dressed up as one.

A human arm in a dead crocodile leads Harrow and Dass to Far North Queensland, battling crocs and crooks in their pursuit of the truth.

While Harrow investigates a baffling crime involving siblings, James brings danger closer to his half-sister Fern than ever before - and pays a high price.

Harrow rides the storm when a deathly ill boy at QIFM needs his help at the very moment Mila Zoric summons him to negotiate his kidnapped son's release. But there's one lightning bolt shock he did not see coming.

Another layer is added to the mystery of Booth's whereabouts and the state of his physical condition when the team discovers that FBI Agent Miller (guest star Kim Raver) has not been entirely truthful with the FBI and the Jeffersonian, keeping vital information from them that could lead them to Booth. Meanwhile, the Jeffersonian gets a surprise visitor, FBI digital forensic scientist Dr. Benjamin Metzger (guest star Josh Casaubon), who works with Angela to try to decode the information the team has been able to uncover regarding Booth's location and the circumstances surrounding his disappearance. Also, Arastoo makes a major decision that affects his and Cam's personal and professional relationship.

On Brennan and Booth's first official day back at their respective positions at the Jeffersonian and the FBI, things get exciting when remains are found at a fish farm under suspicious conditions, prompting them to investigate. After it's discovered that someone harvested several of the victim's internal organs before he was dumped in the water, Angela tracks down the seller and buyer of the organs to try to uncover important details in the case. Meanwhile, Booth readjusts to his position back at the FBI and discovers Aubrey has taken over his old office; Hodgins pushes Angela to showcase her photography work; and Cam struggles with her decision to choose work over her relationship with Arastoo.