Meredith and Maggie support Amelia on an important day; Jo reveals that she has been keeping secrets from Alex while Arizona and Callie deal with the impact of their custody arrangement. Meanwhile, Ben leaps into action to help a friend.

Owen and Amelia take their relationship to the next level; Alex gains some clarity on his future with Jo; and Callie and Arizona continue to struggle with the current custody arrangement.

Callie and Arizona are at odds over Sofia's future, and Stephanie questions the status of her relationship with Kyle. Meanwhile, Alex and April work on a pregnant teen that is readmitted to Grey Sloan Memorial.

Stephanie struggles with boundaries while Callie and Arizona ask their friends for support during a difficult situation.

The doctors work frantically to save a young boy who was accidentally shot. Meanwhile, Arizona is upset when Callie tries to make an important decision about Sophia's future without consulting her.

Miranda continues to deal with the aftermath of Ben's reckless decisions and forms an advisory committee to recommend proper disciplinary action against him. Meanwhile, April and Jackson try to put their differences aside for the sake of their baby, and Arizona makes a decision that could affect her relationship with Callie forever.

Miranda continues to deal with the aftermath of Ben's reckless decisions and forms an advisory committee to recommend proper disciplinary action against him. Meanwhile, April and Jackson try to put their differences aside for the sake of their baby, and Arizona makes a decision that could affect her relationship with Callie forever.

Meredith goes on an ambulance ride with Owen and Nathan to pick up a heart for a transplant patient. Musician & MS patient Kyle Diaz is admitted to Grey Sloan Memorial with a tremor in his hand, and the residents apply for the Preminger Grant. Meanwhile, Catherine continues to insert herself into Jackson and April's business against Richard's wishes.

Meredith takes a step forward with Will but quickly regrets it; Maggie senses a disconnection with Andrew; and Amelia reevaluates her relationship with Owen. Meanwhile, Catherine comes into town and really shakes things up with April and Jackson.

Jackson learns about April's pregnancy, while Alex and the team of doctors handles an hours-long triple-organ transplant surgery. Meredith considers dating again, and Andrew insists on not receiving special treatment after he and Maggie go public.

Richard throws everyone for a loop when he switches the resident and attending pairings, and Arizona takes a huge risk on a woman who is pregnant with quadruplets. Meanwhile, April is faced with a difficult decision.

Meredith, Bailey, Jackson, Callie and Jo travel to a military hospital to perform an extraordinary and extremely risky surgery on a veteran with an advanced tumor. Meanwhile back at Grey Sloan, Andrew is tired of being Maggie's worst kept secret; Ben makes an impulsive surgical decision; and a team of cheerleaders wreak havoc in the ER.

A patient from Meredith's very first surgery as an Intern is readmitted to Grey Sloan Memorial with a new aneurysm, and Amelia takes her case. Meanwhile, Maggie suspects that Richard knows about her relationship with Andrew, and Arizona debates dating again.

The evolution of April and Jackson's relationship is revealed through a series of flashbacks dating back to when they first met. Simultaneously, we follow the years-long progress of one of Jackson's patients.

As the hospital deals with Meredith's trauma, Callie and Maggie perform a risky, experimental surgery on Alex's 15-year-old patient against his professional opinion. Meanwhile, Owen and Nathan are still at odds with each other, and Maggie and Andrew's relationship continues to develop.

Meredith is brutally attacked by a patient, and Penny is the one who discovers her. The doctors of Grey Sloan Memorial rush to stabilize Meredith and remain by her side in the harrowing aftermath.

As the rumor mill around the hospital continues to spiral out of control, Grey Sloan Memorial is flooded with injured firefighters from a nearby wildfire. Maggie struggles to keep things with Andrew professional at work; meanwhile, Jo questions Alex's priorities.

The team of doctors work on a high stakes case of a long time patient, adding additional pressure to an already tense environment. Meanwhile, Bailey wants Ben to kick out their new roommate, and Arizona is eager to get back into the dating world with a new wingman.

A transfer resident arrives at the hospital. Meanwhile, Richard wants his relationship with Maggie to evolve; gossip follows a patient who mistakenly sent his sex tape to his congregation; and April presents a case involving a boy from the Middle East.

Maggie leaves her dinner party and races to the hospital, so April takes over the cooking duties in an attempt to dodge Jackson. Meanwhile, Arizona is anxious about meeting Callie's new girlfriend.

Owen teaches an important lesson to the interns regarding breaking bad news to patients' loved ones. Meanwhile, Arizona's elderly patient tells her not to give up on finding love; and a dinner party gets off to a bad start when the hosts forget about it.

Maggie reflects on her life when her old beau gets married. Meanwhile, Bailey's allegiance is questioned by Richard; Jo tells Stephanie a secret she's been hiding from Alex; and Alex faces a tough decision regarding newborn twins.

The pressure is on as a determined Bailey tackles her first day as Chief; meanwhile, April's marriage to Jackson 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 12th-season opener, Meredith adapts to new roommates. Meanwhile, Jackson gets ready for April's return; Bailey battles to be chief of surgery; and two young patients propel the doctors to reexamine bullying scenarios from their own pasts.