Owen and the 126 crew race to a gender reveal party gone horribly wrong, and a father/son trapped in a cave during a spelunking excursion. Meanwhile, Owen helps T.K. reconcile the past to help his future, Judd and Grace aid Judd's aging father and Michelle learns the full truth about her missing sister, Iris.

Bill joins the military group formed by Ethan, Dominic and Michael. The three men hold a young alien hostage, Isla. Catherine, Sophia and Nathan continue to search for Bill. Adina, and the aliens also set out to find Bill. Chloe accuses the blow when she realizes that Sacha killed Ash. She suggests to her increasingly unstable son to run away with her.

At the university, Sophia watches the videos recorded by Dylan, a young man they found dead, while Catherine focuses on the algorithms he left behind and which decipher the behavior of robots. Thanks to Bill's intervention, Isla manages to flee and join her family.

Korvo tries to get the family involved in repairing the spaceship, but they attend a birthday party instead, where he is inspired to become a magician. Using his computer system Aisha, Korvo creates a technologically advanced magic act; he goes viral and prepares for a Las Vegas show, which will culminate in him leaping through a black hole. Korvo ignores his family's warning that jealous magicians plan to kill him; the family save him from being shot, but he dies when the black hole trick goes awry. The grieving family agree to repair the ship in Korvo's memory, and he reappears, having faked his death to bring them closer together. Yumyulack adds a woman named Cherie to his shrunken collection.

Bill joins the military group formed by Ethan, Dominic and Michael. The three men hold a young alien hostage, Isla. Catherine, Sophia and Nathan continue to search for Bill. Adina, and the aliens also set out to find Bill. Chloe accuses the blow when she realizes that Sacha killed Ash. She suggests to her increasingly unstable son to run away with her.

At the university, Sophia watches the videos recorded by Dylan, a young man they found dead, while Catherine focuses on the algorithms he left behind and which decipher the behavior of robots. Thanks to Bill's intervention, Isla manages to flee and join her family.

The BAU enters into a dangerous game of cat-and-mouse with a convicted serial killer after guards at a Virginia prison intercept a package with evidence relating to the kidnapping of two boys several years ago. The team believes the notorious killer may have information on the boys' whereabouts.

When a bearded, rotund man in a red Santa suit with an ID reading Kris Kringle falls from the sky in Central Park, Castle and Beckett are on the hunt to find the person who killed Santa.

Hotch is apprehended for suspected conspiracy and the BAU suspects a larger plot may be brewing.

When a bearded, rotund man in a red Santa suit with an ID reading Kris Kringle falls from the sky in Central Park, Castle and Beckett are on the hunt to find the person who killed Santa.

A homicide detective relocates to the sleepy, middle of nowhere town of Palm Glade, looking for a change of pace from his old life with the Chicago Police Department. He soon learns this place isn’t so idyllic, as he keeps finding people murdered.

Owen, Michelle and the 126 crew race to a rattlesnake infestation at a young family's home, and attempt to rescue a man with dementia from a dangerous scene that he created. Meanwhile, Owen adopts a firehouse dog with cancer and Michelle finally learns the truth behind her sister's disappearance. Also, a tragic accident shakes the team to its core.

A drunk college student discovers the dead body of a Secret Service agent just before a presidential visit to the area. Booth is ready to hit the ground running and turns to Secret Service agent and former colleague Brandt Walker for information, but is surprised to learn the Secret Service has reservations about Booth's involvement in the case. The team uncovers some shocking evidence that heightens the seriousness of the case, causing Booth to step up for his country. Meanwhile, Brennan is out sick with the flu and former intern Dr. Colin Fisher returns to the Jeffersonian to run lead on the case, but Brennan refuses to be kept out of the loop. Also, Hodgins takes his life into his own hands and turns a corner after a potentially dangerous experiment.

The BAU enters into a dangerous game of cat-and-mouse with a convicted serial killer after guards at a Virginia prison intercept a package with evidence relating to the kidnapping of two boys several years ago. The team believes the notorious killer may have information on the boys' whereabouts.

Hotch is apprehended for suspected conspiracy and the BAU suspects a larger plot may be brewing.

Harrow and Fairley are sent to a double-fatality in Fairley's hometown - a trip that will test their already-strained relationship.

A homicide detective relocates to the sleepy, middle of nowhere town of Palm Glade, looking for a change of pace from his old life with the Chicago Police Department. He soon learns this place isn’t so idyllic, as he keeps finding people murdered.

When an up and coming DJ is killed at a pop star's album release party, Beckett and Castle must dive into the raucous world of New York's music industry.

With Cam's reputation and career on the line, the team travels from overseas to help her solve the case of an unidentified young boy; the Forensics Anthropology Unit lost much of its vigor after disbanding to pursue personal ventures, and it will take the collaborative energy and knowledge of the newly reunited team to unravel evidence, and find closure for the family of the unknown boy.

Castle and Beckett enter the world of adult entertainment when the founder of college girls gone crazy is murdered.

Owen and the 126 crew race to a gender reveal party gone horribly wrong, and a father/son trapped in a cave during a spelunking excursion. Meanwhile, Owen helps T.K. reconcile the past to help his future, Judd and Grace aid Judd's aging father and Michelle learns the full truth about her missing sister, Iris.

Joins the BAU team, which is tasked with capturing a killer who escaped prison with 13 other convicts at the end of last season.

When JJ arrives home shaken after a rough case, she breaks down and tells her husband about the abduction of two children.

As Harrow and Grace investigate the death of a popular health and wellness vlogger, Harrow agitates for the exhumation of Chester's remains.

Colter takes a job locating a missing teen with a unique spiritual gift in an inhospitable mining town

A homicide detective relocates to the sleepy, middle of nowhere town of Palm Glade, looking for a change of pace from his old life with the Chicago Police Department. He soon learns this place isn’t so idyllic, as he keeps finding people murdered.

When an up and coming DJ is killed at a pop star's album release party, Beckett and Castle must dive into the raucous world of New York's music industry.

As Harrow and Grace investigate the death of a popular health and wellness vlogger, Harrow agitates for the exhumation of Chester's remains.

When the remains of a couple are discovered in a cave at National Park, the team must piece together the identity of the man and the woman as well as solve the crime; and Booth's girlfriend and Afghanistan-war correspondent Hannah Burley makes a surprise visit, causing Brennan to re-evaluate her own relationship with Booth.

The BAU welcomes back Emily Prentiss as they are called upon to investigate the disappearance of three women.

Owen helps T.K. reconcile the past to help his future; Judd and Grace aid Judd's aging father; Michelle learns the full truth about her missing sister, Iris.

Castle & Beckett get an up-close-and-personal view of a 'Real Housewives'-esque reality TV series, 'The Wives of Wall Street', when they investigate the murder of the show's rising young star.

The BAU team searches for a serial killer along the Appalachian Trail in rural Virginia.