Amelia confronts a difficult situation, while Meredith deals with the fallout from her conversation with Nathan. Maggie finds herself at an awkward family dinner, Jackson receives big news, and Richard and Bailey search for the stars of tomorrow.

Jackson decides he needs some time off and invites the guys to join him on a day out at sea. Meanwhile, Arizona, April and Maggie treat a woman who’s hiding a deadly secret.

After a roller coaster car falls off the track at the county fair, the doctors at Grey Sloan tend to patients who spark memories about ghosts from their past. The series 300th episode!

A hacker compromises the hospital’s computer system, causing monitors, phones, labs and patient files to all go down. As technology fails them, Bailey attempts to keep the peace but chaos erupts and the doctors are forced to get creative in their methods to treat the patients.

Jo finally faces her estranged, abusive husband Paul Stadler, while Grey Sloan continues to work with the FBI after a hacker has compromised the hospital’s computer system.

April is in charge of the new Grey Sloan Surgical Innovation Contest, and the doctors are eager to start their projects. Meanwhile, Catherine’s old friend has a shocking idea for Catherine and Jackson; and Meredith treats a returning patient who inspires her project.

Maggie's relationship with Clive starts to progress; she invites him over for a game night to meet Meredith and Amelia; Meredith and Jo meet with the owner of the patent to the polymer they need for their project, who is a friend of the family.

Maggie and Jackson are enjoying spending time together, but he must turn his concentration toward the groundbreaking vaginoplasty surgery he has scheduled with Catherine and Richard. Meanwhile, Meredith and Jo hit a roadblock with their contest submission, so Jo helps Bailey with an incoming trauma patient who used to be an astronaut

Amelia, Koracick and DeLuca perform a risky, groundbreaking procedure using ultrasound waves to remove a young patient’s brain tumor. Meanwhile, Meredith and Jo work with different polymers to try to salvage their project submission; and Richard’s AA sponsor is admitted to Grey Sloan with a DNR.

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.

During presentations on Grey Sloan Surgical Innovation Prototypes Day, Arizona shares cookies from an appreciative patient that, unbeknownst to her, contain a special ingredient. Meanwhile, Catherine reveals shocking details to Jackson about his grandfather's past; and Jo steps in mid-operation on a major surgery.

One of Grey Sloan Memorial’s own is seriously injured, making the team reflect on what is truly important to them. Meanwhile, Nicole Herman pays a visit to Grey Sloan and talks to Arizona about an exciting opportunity.

Meredith Grey and the team of doctors at Grey Sloan Memorial are faced with life-or-death decisions on a daily basis. They seek comfort from one another, and, at times, more than just friendship. Together they discover that neither medicine nor relationships can be defined in black and white.

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.

Meredith reaches out to Teddy and helps her talk through some of her personal struggles. Owen and Amelia hide out near Betty’s school after she becomes a flight risk. Meanwhile, Jo wants to get to work on the fellowship, but Bailey’s attention is elsewhere.

Meredith has a patient whose family is celebrating Day of the Dead, making the doctors remember loved ones they have lost. Richard shares unexpected news with Meredith about her father, Thatcher. Meanwhile, Teddy tries to tell Owen that she is pregnant but they get sidetracked, and Jo encourages Link to pursue one of the doctors.

Meredith questions Link’s laid-back approach over a patient’s treatment. Maggie worries that Richard, Jackson and Catherine haven’t come to terms with Catherine’s diagnosis. Meanwhile, Deluca steps up in the O.R. when Owen faces a setback.

Amelia and Koracick tackle a daunting surgery on Catherine while Richard and Jackson hope for the best. Meanwhile, Richard urges Meredith to visit her father, Thatcher, before his time is up.

Patients flood the hospital after gunfire goes off at a parade; a blast from the past throws Maggie off her game on the same day that Meredith tries to talk to her about dating Deluca; Owen and Amelia get some potentially life-altering news.

Meredith breaks a hospital record; the doctors are sent scrambling in the wake of a massive overdose within the community; Jackson wants to take Maggie camping; Levi and Nico's relationship continues to develop.

Ties are strained as Andrew and Carina confront an unforgiving family history. Meanwhile, Teddy and Owen work together on a married couple who is expecting, and Amelia attends a conference for alternative pain relief.

Maggie introduces mood rooms as an alternative approach to medicine. Alex and DeLuca butt heads over an 11-year-old patient who tries to sabotage her own surgery. Jackson and Richard deal with a gender non-binary patient. Meanwhile, Teddy has a pregnancy scare that brings Owen and Koracick to odds.

A patient at the hospital is brain dead after falling into a construction site, and her two sisters must decide whether or not to keep her alive.

After Meredith inadvertently stirs up negative press for Grey Sloan, she tries to make things right with her former colleagues, jeopardizing her community service hours. Station 19’s Ben and Vic bring a young woman into the hospital, and Jackson stands up to Koracick when he goes too far with a patient’s family. Meanwhile, Bailey receives unexpected news; and Owen finds himself at Pac-Gen North, which Alex sees as a recruiting opportunity.

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.

Jo becomes a safe haven volunteer and gets a call that a baby has been dropped off at Station 19. Meanwhile, Meredith moves forward with her life after facing the medical board. Jackson takes a big step in his budding romance with Vic, while Bailey and Amelia swap pregnancy updates.

Following the car crash at Joe’s Bar and subsequent rescue efforts led by the Station 19 firefighters, Grey Sloan doctors work through the night to save the lives of their colleagues. Meanwhile, Amelia worries about sharing her pregnancy revelation with Link. Owen and Teddy take a big step, and Bailey deals with grief over her recent loss.

The crossover starts on Station 19 S03E01 I Know This Bar (I).