Jack and Maya are called to treat people stuck in a subway train and discover a potential threat to the passengers and themselves. Meanwhile, Travis, Ben and Dean get pressured into inviting Sullivan to help repaint walls in Travis' house and come to a surprising conclusion about Sullivan.

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.

One year after escaping the destruction of their planet Shlorp and crashing on Earth, aliens Korvo, Terry, and their child-replicants Yumyulack and Jesse adjust to their new lives. Korvo is determined to repair their spaceship, but Terry introduces him to the television show Funbucket. Realizing that the titular alien is fictional, they create a real Funbucket, who tires of them and befriends humans Travis and Avery. Forced to attend high school, Yumyulack and Jesse are menaced by their classmates and faculty. They shrink a bully named Lydia, hoping to use her to study human behavior. As the Shlorpian family have dinner together, it is revealed that their pet, the Pupa, will one day evolve and destroy Earth to terraform a new Shlorp.

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.

While working at their non-profit clinic three hours outside of Atlanta, Nic and Mina treat a patient with a failing heart VAD, forcing them to find a new battery in time to save her life. Conrad gets a call from a previous patent in crisis after being sued by Red Rock for medical expenses he can't afford. Meanwhile, Devon's VIP patient, Nadine, returns to the ER and Cain tries to get close to Bell's business partner from the supplement company.

When Andy, Maya and Dean respond to a call, they find an injured woman with amnesia; but soon into the treatment process, they realize there is much more to her story. Meanwhile, Captain Sullivan takes Ben and Jack on a house call that quickly becomes a close call for the patient they're treating, while Ryan may not have seen the last of his father, Greg.

Desire proves to be a dangerous emotion on "Desperate Housewives." Lynette and Tom uncover the unsettling truth about son Porter; Gabrielle suspects Carlos' best client has ulterior motives; Bree's moment of weakness could bring her great embarrassment and shame; and Katherine's not so little secret is unveiled. Meanwhile, Susan learns of Jackson's true passion, and Mrs. McCluskey's sister unearths a disturbing fact about Dave.

It will be a night to remember. Susan's daughter comes to visit with her surprising new boyfriend; Gaby uncovers the unsettling truth about Mrs. Hildebrand's past; Katherine has a confession to make to Susan; a reporter looks to expose Bree's imperfections; and Lynette learns Porter and Anne Schilling plan to leave Fairview and disappear. Meanwhile, everyone has gathered at a club to see the guys play in the annual "Battle of the Bands" when a fire erupts, threatening the lives of those in attendance. Some will fall as a hero will rise.

While working at their non-profit clinic three hours outside of Atlanta, Nic and Mina treat a patient with a failing heart VAD, forcing them to find a new battery in time to save her life. Conrad gets a call from a previous patent in crisis after being sued by Red Rock for medical expenses he can't afford. Meanwhile, Devon's VIP patient, Nadine, returns to the ER and Cain tries to get close to Bell's business partner from the supplement company.

The Grey Sloan Memorial doctors grapple with the aftermath of the car crash that involved some of their own. Meredith works to save Dr. Hamilton's life; Levi is impacted from his latest loss.

Schmitt must face the Morbidity and Mortality Conference. Meredith convinces Nick to scrub in on a surgery in Seattle. Jo faces her feelings.

Desire proves to be a dangerous emotion on "Desperate Housewives." Lynette and Tom uncover the unsettling truth about son Porter; Gabrielle suspects Carlos' best client has ulterior motives; Bree's moment of weakness could bring her great embarrassment and shame; and Katherine's not so little secret is unveiled. Meanwhile, Susan learns of Jackson's true passion, and Mrs. McCluskey's sister unearths a disturbing fact about Dave.

It will be a night to remember. Susan's daughter comes to visit with her surprising new boyfriend; Gaby uncovers the unsettling truth about Mrs. Hildebrand's past; Katherine has a confession to make to Susan; a reporter looks to expose Bree's imperfections; and Lynette learns Porter and Anne Schilling plan to leave Fairview and disappear. Meanwhile, everyone has gathered at a club to see the guys play in the annual "Battle of the Bands" when a fire erupts, threatening the lives of those in attendance. Some will fall as a hero will rise.

The pressure of the Kennedy name weighs on John. Carolyn impresses at Calvin Klein. An unlikely connection forms at a charity event.

Upon meeting with a high-profile soccer player suffering from mysterious symptoms, Conrad ends up back at Chastain and faces an angry Logan Kim. When Bell and the Raptor come up empty-handed in regard to a diagnosis, the doctors take note on how talented Conrad truly is. Nic springs into action when she notices Kyle falling into a deep depression and fears he could be suicidal. Meanwhile, Devon butts heads with Irving over patient space and Mina realizes she has become attached to baby Michelle.

Meredith, Amelia and the team prepare for Dr. Hamilton's long-awaited groundbreaking surgery while Bailey receives an unexpected offer. Owen's impatience makes him a difficult physical therapy patient, forcing Link to intervene.

Nick whisks Meredith away to his Minnesota cabin for a romantic weekend, leaving Winston and Maggie to care for Meredith’s children. Meanwhile, Amelia and Kai grow closer.

The road to recovery begins in the aftermath of the deadly fire that shook the citizens of Fairview. For Gaby and Carlos, injuries sustained in the fire lead to a fortunate discovery. But for most, the consequences are less forgiving. Lynette and Tom vow to protect son Porter at any cost; Susan must learn to let go of the man she loves; and Orson's attempt at a good night's sleep puts Bree in a most precarious, though amusing, position on the day of her big cooking demonstration.

Darkness lifts and brings resolution for some, while others suffer in the depths of despair. Lynette does what any mother would do to protect her son; Carlos realizes the sacrifices Gaby has made for their family; Bree longs to prove to Andrew she has accepted him for who he is; Katherine finds happiness; Susan and Mike recognize the fate of their relationship; and Dave begins to lose his grip.

Jack and Maya are called to treat people stuck in a subway train and discover a potential threat to the passengers and themselves. Meanwhile, Travis, Ben and Dean get pressured into inviting Sullivan to help repaint walls in Travis' house and come to a surprising conclusion about Sullivan.

An inmate violently escapes from a prison transport van. Then a witness in the escaped prisoner's murder trial is found dead. The accused murderer shows up and pleads with Megan that he is innocent and being framed.

Megan probes more deeply into her father's suicide so much that she finally gets some closure.

The pressure of the Kennedy name weighs on John. Carolyn impresses at Calvin Klein. An unlikely connection forms at a charity event.

A high school baseball pitcher Justin finds that he is haunted by the former baseball star pitcher. The ghost is out for revenge on the coach who he blames for his death.

Megan probes more deeply into her father's suicide so much that she finally gets some closure.

The pressure of the Kennedy name weighs on John. Carolyn impresses at Calvin Klein. An unlikely connection forms at a charity event.

Jack and Maya are called to treat people stuck in a subway train and discover a potential threat to the passengers and themselves. Meanwhile, Travis, Ben and Dean get pressured into inviting Sullivan to help repaint walls in Travis' house and come to a surprising conclusion about Sullivan.

The road to recovery begins in the aftermath of the deadly fire that shook the citizens of Fairview. For Gaby and Carlos, injuries sustained in the fire lead to a fortunate discovery. But for most, the consequences are less forgiving. Lynette and Tom vow to protect son Porter at any cost; Susan must learn to let go of the man she loves; and Orson's attempt at a good night's sleep puts Bree in a most precarious, though amusing, position on the day of her big cooking demonstration.

Darkness lifts and brings resolution for some, while others suffer in the depths of despair. Lynette does what any mother would do to protect her son; Carlos realizes the sacrifices Gaby has made for their family; Bree longs to prove to Andrew she has accepted him for who he is; Katherine finds happiness; Susan and Mike recognize the fate of their relationship; and Dave begins to lose his grip.

A schizophrenic girl at a mental institution is murdered. Megan and Tommy interview a young patient who seems sane and lucid, she tells them she saw the killer climb down from a heating vent in the ceiling, but he meant to kill her, not the victim.

Dr. Addison Forbes Montgomery returns and graces the Grey Sloan halls with her experience and expertise as she attempts to help Richard teach the newest crop of residents. Meredith has a decision to make; Link confides in Teddy.

Richard recruits Meredith and Bailey to help him launch a new program. Addison's patient has complications from a procedure. Jo helps a woman who goes into premature labor.