Sloan returns to Mark's apartment, just as she's going into labor, and Teddy, Mark and the still-fighting Callie and Arizona are there to help with the birth and to get Mark through his grandson's pending adoption. Meanwhile Teddy sees Derek's invitation to illustrious cardiothoracic surgeon Tom Evans' as a threat to her future employment at the hospital, and the team work on a crab boat captain who has been stabbed with a giant shark hook.

A gas tanker explodes on a Seattle highway, causing multiple injuries, including paramedic Matthew. Meredith and Jo help a frantic mother whose child is suffering from a mysterious illness. Owen bonds with a young boy whose parents are in critical condition. Meanwhile true colors are revealed when Alex is forced to work with Jo's boyfriend on an ailing patient.

A betrayal intensifies the issues between Cristina and Meredith; Matthew and April make a decision about their relationship; Bailey faces difficulties with Ben's return.

Jackson is given the daunting task of delivering disappointing news to the doctors. Meanwhile, Derek's sister Amelia drops by for a surprise visit, Richard surprises Catherine in Boston and when Bailey gets frustrated by the slow pace of her research, she makes a risky decision.

As Derek prepares for his move to DC, Meredith keeps herself busy at the hospital. Meanwhile, Jackson and April deal with difficult news, and Arizona and Amelia discuss how to best approach Dr. Herman.

The doctors of Grey Sloan Memorial Hospital are forced to put their emotions aside when a catastrophic event occurs.

The pressure is on as a determined Bailey tackles her first day as Chief; meanwhile, April's marriage is in jeopardy and she finds herself unable to address her problems; Meredith struggles to juggle all her responsibilities and Amelia works to define her relationship with Owen.

In the midst of the sisters’ dinner party, Maggie ditches her cooking duties to rush to the hospital. Meanwhile, April steps in to help cook as an attempt to avoid Jackson, and Arizona nervously waits to find out more about Callie’s new girlfriend.

There is plenty of turmoil after Richard messes with the staff pairings. Arizona takes a risk to help a woman who is pregnant with quadruplets.

A difficult surgery brings back pivotal memories for Meredith, Richard, Owen and Stephanie, as they work together to save a life.

When Maggie’s mom’s health deteriorates, the doctors are at odds over how to treat her. Meanwhile, Richard comes to grips with Bailey’s betrayal over the Residency Program.

Harper Avery arrives at Grey Sloan, putting Bailey on edge. A familiar face from Meredith’s past returns as a patient, and Amelia tries to manage a secret.

An agent from ICE shows up at Grey Sloan in search of an employee who may be working in the U.S. under DACA. Alex’s patient Kimmie wants to leave the hospital to enjoy her final days, but Alex feels differently. Meanwhile, Arizona treats Matthew Taylor’s baby and April wants to do whatever she can to help.

The doctors at Grey Sloan Memorial vie for a new position. Meredith is seemingly distracted and struggles to stay focused, and Maggie finds herself the keeper of a big secret while Amelia and Owen try to figure out their relationship. Meanwhile, Jo and Alex's honeymoon doesn't go exactly as planned.

New doctors continue to shake up the hospital in typical Grey Sloan manner. Meredith bonds with a patient while Jackson struggles with the meaning behind recent experiences; and after making a life-changing decision, Jo forms an unexpected alliance.

Seattle is hit by a huge wind storm and Grey Sloan becomes inundated with patients. Alex and Jo are stuck at home and decide to make the best of it by having a second honeymoon, while Meredith confronts Richard about getting his life back on track. The winter finale.

When the power goes out at Grey Sloan, the doctors are left scrambling to save their patients' lives; Owen, Amelia and Teddy confront their complicated situation.

Owen and Teddy have to deal with the surprise arrival of Megan Hunt, who knows nothing about their situation. Catherine preps for her first surgery back on a war veteran who’s not emotionally prepared for his procedure. Meredith worries about DeLuca operating alone with Richard.

The doctors operate on a man who crashed into Maggie's car as Owen, back from paternity leave, struggles with Tom's new position. Meredith's recent firing doesn't stop her from diagnosing those around her. Richard and Alex start anew and it's not easy.

Meredith faces the medical board as her future as a doctor remains uncertain, and she’s forced to reckon with her past in some challenging ways. Meanwhile, the interns are put to the test as they are each vying to be the most successful on their respective cases in the absence of some of the attendings.

Meredith and Carina question DeLuca’s uncharacteristic behavior when he volunteers to perform a life-threatening task during a blizzard. Meanwhile, Bailey tries to help Joey with his future, while Richard trains a new intern at the hospital.

The Grey Sloan doctors continue to face their new COVID-19 reality and deal with a familiar and stubborn patient. Koracick is put in charge of the interns who recently joined the hospital ranks and Link operates on a sex therapist. Elsewhere, Maggie finds comfort in Winston's virtual presence.

Levi gets accepted into the vaccine trial. Meanwhile, Amelia and Owen treat a car crash patient, and Hayes and Jo are met with Luna’s legal guardian.

It’s wedding day for Maggie and Winston. Meanwhile, Meredith takes on a new role at the hospital, and Jo makes a life-changing decision.

As the city of Seattle revels at the Phoenix Fair celebrating the city’s rebirth post-COVID, the Grey Sloan doctors treat a patient who encounters illegal fireworks. Meanwhile, Bailey has her sights set on hiring new doctors, but she’s having trouble finding viable options. Owen and Teddy attempt to take the next step in their engagement, and Meredith has a surprising opportunity when she meets a dynamic doctor from her mother‘s past.

The crossover starts on Station 19 S05E01 Phoenix from the Flame (I).

It's Thanksgiving, and while Meredith faces travel complications due to the weather, Nick steps in to help in more ways than one; Richard and Bailey seek out emergency surgeries; Amelia and Link reconnect.

Due to a blood shortage, Grey Sloan Memorial is setting up a voluntary donation center. Meanwhile, Nick asks Meredith for help with his patient and Winston is hung up on his relationship with his brother.

The attending surgeons and interns work together to solve a medical mystery when a college kid comes in with what first looks like food poisoning but has escalating and dire complications. Meanwhile, Jo spends her day off with Bailey.

Addison makes a special appearance at Grey Sloan to welcome Bailey’s new OB/GYN trainees. Maggie’s lung transplant is derailed, and Nick bonds with Lucas — before the day takes a shocking turn.

Simone's wedding day arrives as Jo and Link's relationship hits a major turning point.

The attending surgeons fly to Boston, forcing a reunion between Nick and Meredith. Bailey gets a big surprise.

Meredith rethinks her plans. The interns are on thin ice following a patient's death. Simone and Lucas are immediately tested in an emergency. Richard confides in Bailey. Teddy's fate is revealed.

After firing some of Grey Sloan's best, Catherine continues to interfere with Meredith and Amelia's research. Accidents at a climate change protest bring unique cases to the hospital, and Bailey encounters a blast from the past.

While the interns are excited to transition to second-year residency, an ordinary day at Grey Sloan takes an unexpected turn when a medical emergency unfolds in the operating room, endangering lives inside the hospital.