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.

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.

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.

Catherine is in Los Angeles getting the new foundation ready and summons Meredith and Koracick to visit for a highly confidential consult. Meanwhile, one of the nurses is 28 weeks pregnant and collapses at the hospital while talking to Richard.

A patient gives Meredith some clarity on her dating situation around the holidays. The strain on Bailey and Ben’s marriage comes to a head. Meanwhile, Betty drops a bomb on Owen and Amelia.

Meredith finds herself having to side with either Alex or DeLuca during a difficult situation, but she doesn’t want to betray either of them. Meanwhile, Maggie reveals details about her personal life that cause a public stir, and Levi struggles with whether or not to tell his family about Nico.

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.

Richard preps to present his PATH pen at the LA Surgical Innovation Conference but becomes distracted by his issues with Catherine. Maggie and Teddy run into people from their past at the same conference, while Hayes relives moments from when he met his late wife.

The Grey Sloan doctors spring into action after an explosion rocks Seattle, with the incoming trauma hitting close to home. Owen experiences PTSD after he hears the explosion, while his sister Megan enlists help from Winston and Hayes in confidence. In Minnesota, Meredith and Amelia meet up with a familiar face who assists in their study.

The crossover starts on Station 19 S05E05 Things We Lost in the Fire (I).

A former patient of Link’s, Simon, is in the ER with his pregnant wife; and Bailey receives an offer from Nick.