Richard is desperate for Derek and Meredith to accept Adele into their Alzheimer’s trial, but will Adele stand in her own way? Meanwhile Mark and Arizona have conflicting ideas of…

Meredith must choose between her fertility treatments and her eyesight when she begins having trouble seeing, Mark makes it clear to Callie and Arizona that he takes his role as…

Meredith, looking to prove she is Chief Resident material, learns that anything and everything can happen in an hour’s time when she steps up to run the ER for a…

Thatcher Grey, Meredith and Lexie’s father, returns to Seattle Grace with stomach pains and a new, twenty-something tattooed girlfriend, Danielle. Meanwhile, Alex clashes with the new OB, Dr. Lucy Fields,…

Derek breaks ground on his Alzheimer’s clinical trial and Meredith can’t help but feel left out; Bailey’s attempt to take the hospital into the age of new media with live…

Arizona tries to reconcile with Callie, who has big news to share; Teddy faces an important decision; the residents receive new interns; the Chief makes an announcement.

A gunman opens fire at a local college, sending mass casualties to the hospital; Arizona’s return is not warmly received.

Derek takes Cristina out on a fishing trip; Teddy tries to help a patient who lacks the proper insurance to seek medical treatment.

The residents are on their own with the dreaded night shifts while the attendings go out to play to celebrate Derek’s grant for his clinical trial.

A team of doctors tries to save the life of a political figure from the Middle East; Cristina decides to decorate her new place and throw a housewarming party; Alex…

Owen puts the residents through a rigorous trauma certification drill; Cristina is left alone to monitor an ill lung transplant patient.

A documentary crew visits the hospital six months after the shooting to document the road to recovery for doctors and patients; Meredith helps Cristina put on a brave face for…

As part of their training, Seattle Grace’s residents are put in charge; the attending surgeons compete for a million-dollar grant.

Issues surface when Derek’s estranged sister, Amelia (Caterina Scorsone), visits unexpectedly; Meredith and Derek continue to try to ease Cristina back into surgery.

Derek and Meredith visit the obstetrician and receive disturbing news; Lexie notices April and Meredith growing closer; Jackson tries to get ahead in the operating room.

Meredith finally tells Derek about her pregnancy and miscarriage; during a surgery, Cristina experiences PTSD; Bailey won’t let Alex operate until he has the bullet in his chest removed.

In the wake of the shooting at Seattle Grace-Mercy West, the doctors find themselves in a frenzy: Christina and Owen will be getting married, and others are trying to deal…

Deborah and her team head to LA to pitch her new set as a comedy special.

Deborah prepares to take the stage for her taping as Ava deals with a new opportunity.

A girls’ night out finds Ava attempting to connect with her mother – and Deborah embracing some unexpected company.

An impromptu detour finds Deborah reckoning with long-held guilt while reconnecting with a former comedian friend.

While Deb struggles to connect with her audience on a cruise, Ava finds herself an unexpected hit.

Deborah embraces tour life. Ava grapples with the value of honesty. Jimmy learns the harsh realities of Hollywood dealmaking.

Deborah continues to workshop her material on the road, as Ava adapts to a new lifestyle. Marcus is overwhelmed by life without Wilson.

Deborah eagerly anticipates trying out her new material on the road, while Ava dreads the fallout of an explosive email.

Cristina and Meredith’s surgical skills are put to the ultimate test.

Seattle Grace Hospital is hit with a crisis like no other in its’ history.

An elderly patient admitted into the E.R. for a heart condition sees a familiar face, a long lost love who happens to be in the E.R. as well for a…

Bailey preps the team with mandatory sensitivity training prior to admitting a 700-pound patient with compounded medical issues, and the case proves to be challenging in every sense of the…

Sloan returns to Mark’s apartment, just as she’s going into labor, and Teddy, Mark and the still-fighting Callie and Arizona are there to help with the birth and to get…

When Alex’s younger brother, Aaron, shows up at Seattle Grace-Mercy West with a hernia, it’s up to Alex to get Bailey’s approval for his pro bono surgery. Matters are further…

When Teddy’s patient seeks to end treatment and her life, she turns to Hunt for help. The situation triggers Hunt’s memories of his life at war and his past relationship…

A patient who needs an extremely difficult surgery comes to Seattle Grace, and it’s Richard and Owen who vie for the opportunity to tackle it. But the decision lies in…

When famous surgeon Dr. Harper Avery is rushed to Seattle Grace-Mercy West, the staff is surprised to discover that one of their own is related to this legend, and his…

In his new role as Chief, Derek restores the hospital lecture series, and Richard, Bailey and Callie present to the group pivotal surgical cases from their pasts Bailey reflects on…

It’s Valentine’s Day, and the doctors must treat dozens of injured people after the roof collapses at a popular romantic restaurant; Derek tries to manage his busy schedule as Chief…

As Derek begins his role as interim chief, he faces a potential lawsuit when Bailey and Meredith’s patient awakens from anesthesia mid-surgery. Meanwhile, Teddy refuses to place Cristina on her…

After learning of Richard’s drinking problem, Derek confronts him for the sake of his friend and the hospital, Izzie returns, hoping to reconcile with Alex, and tensions run high between…

Mark flies Addison to Seattle to help with a difficult procedure on his pregnant daughter, Sloan, Owen questions Teddy’s motives when she assigns Cristina the lead on a complicated surgery,…

As Thanksgiving, Christmas and New Year’s pass, Miranda gets a visit from her father, William who disapproves of her choices in life. Mark and Lexie cope with an arrival of…

A generous 25 million donation is offered to Seattle Grace by the parents of Arizonas 10-year-old patient, she finds herself in a conflict of interest when his condition worsens. Cristina…

Owen recruits Dr. Teddy Altman, a former Iraqi veteran, as the new cardiothoracic surgeon. Cristina questions her abilities in the E.R. and relationship with Owen. Izzie returns to Seattle Grace…

When Isaac has an inoperable tumor wrapped around his spine, he wants Derek to do the impossible. Derek tests the Chief’s authority when Richard objects to moving forward with the…

After a burn victim unexpectedly dies in the midst of a chaotic ER, the Chief and board member Jennings interrogate the residents to find the culprit, as all the Mercy…

The residents of Seattle Grace and Mercy West vie for surgeries and their careers as day one of the hospital merger begins. Meanwhile, Arizona stands by an enraged Callie when…