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.

Seattle firefighters Ben Warren and Andy Herrera head to Grey Sloan after rescuing two boys who were injured in a house fire; the doctors work on their projects for the surgical innovation contest; Amelia brings Tom Koracick in to consult.

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.