After a long six months, Grey Sloan Memorial has reinstated its residency program. A group of talented and striving young interns has been recruited as the attending surgeons work to rebuild the program to its former glory. Meredith, still functioning as the interim chief, sees Nick for the first time since she rejected his offer to move to Minnesota. Meanwhile, Bailey tells Richard she is not ready to return to work. Levi works up the courage to break disappointing news to Jo, and things turn awkward when Link realizes he has met one of the interns already. With Amelia and Maggie’s help, the new doctors are thrown into their first day on the job dealing with injuries from a recent tornado.

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.

Bailey recruits the interns to create a series of social media videos informing teens about sexual health. The videos, filmed at Grey Sloan in front of a group of high schoolers, hit home as a student has medical complications during her visit. Elsewhere, Meredith and Maggie learn something new about Zola.

It’s Halloween night at Grey Sloan Memorial. Meredith and Nick try to spend some alone time together; Levi is stressed due to overworking, and Winston and Owen have the interns practice trauma training on a real cadaver.

Bailey and Addison take a road trip to volunteer at a family planning center, but a patient’s ectopic pregnancy leads to complications. Elsewhere, the interns play detective about Lucas’ relationship with Amelia, and Meredith catches up with Jackson on a trip to Boston.

On the heels of life-changing news, a thunderstorm hits Grey Sloan. The attending surgeons and interns work together to save an injured reporter and family affected by the storm. Meanwhile, a beloved author undergoes a risky surgery, and complications from the storm arise.

It’s Meredith’s last day at Grey Sloan Memorial and the doctors plan a goodbye surprise, while Nick confronts her about the future of their relationship. Elsewhere, the interns compete to scrub in on Maggie and Winston’s groundbreaking partial heart transplant procedure, and Richard asks Teddy an important question.

Teddy makes a challenging decision. Meanwhile, Maggie and Winston aren’t on speaking terms, and Link leans on Jo for emotional support as he preps for a surgery on a well-known athlete. Simone and Lucas are surprised by an unlikely visitor.

Simone is met with a life-changing decision upon the return of someone from her past. Blue shadows Maggie on a risky procedure, while Jo and Link tend to a pregnant woman. At the intern house, Lucas and Mika throw a party filled with surprises.

Catherine returns to Grey Sloan for a surgical case that makes Lucas and Blue queasy. Amelia treats a possible cancer patient with a family that’s a little too supportive. Owen takes his medical future into his own hands, much to Teddy’s surprise.

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.

In the immediate aftermath of shocking events at the clinic, the hospital goes on lockdown and the Grey Sloan doctors split up to save multiple lives; Maggie lands in hot water with Winston; Jules' roommate makes a surprise appearance.

A bull rider shows up at Grey Sloan with severe injuries, forcing Maggie, Amelia, Owen and Blue to examine their own biases. Elsewhere, Simone can’t find anyone to be her maid of honor, and Mika takes drastic measures to pay down her student debt.

It’s Maggie’s last day. Amelia’s relationship with Kai is tested, and Ben worries as Bailey’s doxing intensifies.

With Levi’s help, a patient celebrates a milestone. Jo processes a difficult diagnosis, and Maggie and Winston decide their future.

Amelia takes her personal problems out on her work colleagues, and the threats against Bailey come to a terrifying head. Lucas and Jules make a risky decision on a patient, and Mika struggles with burnout.

Teddy calls an emergency meeting to discuss the intern program. Link wrestles with his own self-doubt as he preps for a massive surgery, and Nick shares some much-needed guidance with a struggling Lucas.

Richard and Teddy make an exciting announcement. Jules and Blue butt heads over Maxine’s care while Lucas helps an artist decide on a risky procedure. Jo and Mika tend to Sam as Simone faces a life-changing decision.

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.

Bailey tells the interns they must complete dozens of basic procedures before being allowed back in surgery; things are awkward between Simone and Lucas; Amelia comes up with a solution to a complicated surgery.

Meredith and Amelia work to secure funds for their research while Amelia finds herself at odds with a new attending. Levi runs into someone from his past, and Owen gives Winston advice. Lucas ditches Mika, forcing her to treat a patient alone.

Dr. Arizona Robbins returns to Grey Sloan for a particularly complicated case. The interns are interrogated about their past mistakes, while Teddy is eager to return to work after her health scare.

It's all hands on deck at Grey Sloan when a group of medical students is injured by a floor collapsing at their white coat party. Jo and Link are forced to talk about the future, while Jules confronts Winston about his attitude.

Mika and Teddy receive a patient from a nearby penitentiary. Catherine pushes back on Link and Monica's treatment plan for a VIP. Bailey tries to integrate wellness into the residency program.

An unexpectedly complex case brings back painful memories for Simone. Jules and Blue make a high-stakes bet on who can finish their procedure log first. Richard suspects Winston is avoiding him.

Owen and Teddy have the day off but encounter an injured civilian. Monica enlists Amelia's help with an operation on a young patient. The interns complete their procedure logs, allowing them back into the OR.

Just as Amelia comes to a realization, Teddy encourages her and Meredith to speed up their Alzheimer's research over fear of Catherine finding out. Mika finds herself caught in the middle of Link and Jo; meanwhile, Lucas receives bad news.

Wildfires threaten the Seattle region, leading to a flood of patients and emergency procedures. The doctors juggle overcapacity in the ER, complex surgeries and personal stress. Meanwhile, Meredith makes a rash decision that can't be undone.

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.

Meredith and Catherine continue to disagree, and Meredith confides in Bailey for support. Richard, Winston and Lucas spend the day outside of the hospital, and Blue deals with a relationship from his past. Levi meets the new hospital chaplain.

Simone and Lucas work to balance their relationship while competing to assist on an awake kidney transplant. Teddy offers Amelia a new opportunity, and Ben's interview doesn't go as planned. Meredith's secret causes tension with Richard.

Mika struggles with a life-altering personal matter. Meanwhile, Bailey and Ben navigate their personal and professional roles, while Levi finds a connection in an unlikely place. Jo and Link get surprising news.

During a high-stress day at Grey Sloan Memorial, the fates of a patient in critical condition and a helicopter-bound medical team hang in the balance. Teddy and Owen work on their marriage, while Bailey, Blue and Link treat a hospital employee.

Teddy and Owen plan a date night that gets derailed in more ways than one, while Jo struggles to do it all at home. Mika adds more to her plate to make up for taking time off to be with her sister, and Levi is faced with a monumental decision.

The doctors at Grey Sloan must put aside their emotions under intense circumstances. Levi asks James a shocking question that could impact their future.

In the midst of a deadly heat wave, the team at Grey Sloan struggles to keep up with an overwhelming amount of patients. Amelia and Winston face a challenging surgery, while Jo and Lucas run an errand for the hospital that takes an unexpected turn.

The aftermath of the convenience store shooting brings chaos to Grey Sloan. Ben hits a wall with his new emergency preparedness plan. Romantic tensions surface for Owen, while Amelia and Winston disagree over the surgical plan for a young patient.

Meredith and Nick return to Grey Sloan to treat a liver transplant patient. Meanwhile, Bailey hosts an intern retreat at her home, and Winston and Ben aid an unexpected crash victim.

Following a difficult case, the team faces the complexities of medical ethics. Meanwhile, Bailey continues to navigate her working relationship with Ben, while a group of college students on a scavenger hunt causes chaos around the hospital.

Meredith and Amelia prepare a funding proposal for their Alzheimer’s research. Meanwhile, Teddy and Owen hit a breaking point in their marriage, while Jules has an awkward encounter with Dr. Beltran.

Amelia and Simone attempt to perform a high-stakes and groundbreaking brain surgery. Teddy and Bailey attend a medical conference and run into Dr. Cass Beckman. Meanwhile, Jo struggles with her irritation toward a younger OB-GYN.

Bailey welcomes a renowned surgeon, whom she greatly admires, to Grey Sloan to help on a challenging case. Meanwhile, Teddy, Owen, Jules and Ben team up to save the life of a patient who has been impaled by an ice pick.

A window washer’s platform crashes through a hospital window, testing the Grey Sloan team’s limits. Meanwhile, Blue and Simone clash over their living arrangements, and Lucas strives to impress Catherine while on her service.

Amelia undertakes a high-risk brain surgery on a young patient, while Winston and Jules disagree over how to handle their trauma patient's family. Jo and Link struggle with wedding planning.

Jo and Link's wedding day arrives, along with some visitors. Meanwhile, Teddy and Owen are met with a familiar face seeking treatment, and Lucas disagrees with Simone on how to approach a patient's worsened condition.

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.