The doctors from Grey Sloan Memorial Hospital spring into action to save the lives of two girls with a powerful story. Meanwhile, Meredith tries to cope with the fact that Amelia is now living with her, and Jackson prepares for April's return back to Seattle.

The pressure is on as a determined Bailey tackles her first day as Chief; meanwhile, April's marriage 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.

When Maggie gets an invitation to her ex-boyfriend's wedding, she starts to reevaluate her choices.

Owen suggests the interns learn about breaking bad news to patients' families.

Maggie leaves her dinner party and races to the hospital, so April takes over the cooking duties in an attempt to avoid Jackson. Meanwhile, Arizona is extremely anxious about meeting Callie's new girlfriend, who happens to be a familiar face in Meredith's life.

Penny's first day gets off to a rocky start. April brings a young patient from overseas with tumors on his hands. Jo and Stephanie's feud continues.

A high-stakes case is tackled by a team of doctors, and the atmosphere grows tense. Meanwhile, Bailey pressures Ben to evict their roommate; and Arizona enthusiastically reenters the dating scene with a new wingman.

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. Also, Alex decides to make a big step in his life.

Meredith is attacked by a patient, and Penny finds her injured. The staff of Grey Sloan Memorial is standing by Meredith trying to save her life.

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.

Flashbacks reveal the evolution of April and Jackson's relationship, beginning with their initial meeting, and the years-long process of one of Jackson's patients. Also, April finds out something life changing.

A patient from Meredith's first surgery as an intern is re-admitted to the hospital with an aneurysm; Maggie thinks Richard knows about her relationship with Andrew; Arizona considers dating again.

Meredith, Jo, Bailey, Callie and Jackson head to a Veterans hospital for an spectacular yet unusual surgery. Meanwhile, a group of snobby cheerleaders come into the ER and Warren makes a risky decision.

Richard swaps pairings among the residents and attendings, baffling everyone. Meanwhile, Arizona makes a bold decision as she treats a woman who's carrying quadruplets; April faces a tough choice.

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

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.

April and Arizona find themselves arguing in switched positions. Richard tries to stop Catherine interfering in others' lives. Meanwhile residents are motivated to compete for a great research grant.

After a missing child forces the hospital into lockdown, Ben decides to operate on a pregnant mother without the proper surgical equipment. Miranda, as Chief, is faced with the repercussions of the event.

Miranda is faced with the repercussions of Ben's actions; Miranda forms an advisory committee.

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.

Stephanie's relationship to Kyle becomes complicated. Meredith encourages Amelia and Owen to take a chance and choose to be a real couple. Arizona and Callie are at odds and put their friends in the middle of an uncomfortable situation.

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.

Owen and Amelia take their relationship to the next level; Alex has a clearer view of his future with Jo; Callie and Arizona struggle with custody arrangements.

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.