Our history defines us. Cristina struggles with hers, as Colin Marlow says she's not the marrying kind, even as she plans to wed Burke next month. A young woman who Alex says was raised by wolves (Meredith), must deal with her "fake mother" (Susan), who's determined to be a part of her life. The Chief looks to move on after his painful divorce from Adele, and when we first see Isobel Stevens, she's coming back from confession.
As in the confession. At church.
But her inexplicable night of passion with George is nothing compared to the shock Izzie gets next.
Eleven years ago, Izzie got pregnant and gave her baby up for adoption. Now the parents of her daughter, Hannah, are at Seattle Grace and asking Izzie for help. Hannah is in dire need of a bone marrow transplant, and Dr. Stevens - the biological mother - is a strong match. Suffice it to say, it's too much for our girl to take. She retreats to the women's room in tears, and confesses all to a concerned Dr. Bailey.
With ulterior motives as plain as day, Colin asks Cristina to assist him on a unique "piggyback" heart surgery. He and Preston angle for her affections even as they prepare the patient for his operation... and even during the procedure. Colin chastises Burke as he conducts the surgery, then takes a shot at Cristina when he catches her trying to console Preston afterwards.
As Marlow splits town, Cristina can get back to being herself... assuming she wants to be or knows who that is.
In the race for Chief, a sullen Derek pleads for Richard's support with the board. Mark also seeks Richard's support... as a wing man. That's right, to pick up girls. It's a recipe for disaster. Richard asks if it's just a ploy on Sloan's part to get him laid in return for his vote with the board. A wry smile is all Mark offers.
Despite continued wrangling, Derek doesn't get the Chief's backing, but not for his lack of qualifications - it's because Richard has seen what the job takes out of a man and he promised Ellis Grey he'd look after her daughter.
Derek may be the top candidate, but he is therefore left wondering whether Meredith his forever compromised his ambitions of becoming head of surgery.
Mark may not get a wing man, but Jane Doe gets a name. She's Shannon Marie. When Seattle Grace releases photos of her new face to the news stations, a married couple claims her as their daughter. The blood type (and her lack of tonsils) is a match. All is well until the would-be mother pulls a 180 and decides Shannon/Jane Doe is not her daughter.
But is she? Does her husband merely want it to be so? Is she just unwilling to accept the possibility that things might never be the same? Does Alex secretly - or not-so-secretly - wish to keep Jane Doe all to himself? At the end, when she learns she may not be released to be with her newfound parents, Jane/Shannon snaps at Alex, finally releasing the frustration and pain she's been harboring throughout the entire ordeal.
Hannah says she's not ready to see her biological mother, but a sad Izzie nonetheless agrees to the bone marrow transplant. Bailey tries to keep the process discreet, but George insists on knowing what the heck is going on. It's becoming more and more clear that he loves her as he holds her hand through the painful spinal injection and helping her get dressed (and into a wheelchair) after.
As they watch Hannah prepare for the transplant - unbeknownst to anyone but them - Izzie stops short of telling George she loves him. Barely. She says she can't live without him... and that the love they made wasn't something evil, and that she needs him now and in the future. Their history defines them... but what will the future hold?