Let the Angels Commit

Meredith visits Derek at his trailer when he does not call her for a week after she tells him about breaking up with Finn. She finds him only clad in a towel, with a tall beautiful woman on his bed. Shocked, Meredith flees the trailer while Derek tries in vain to chase her. It turns out the woman is his sister, Nancy, who does not seem to approve of him dating Meredith and proceeds to label her a slutty intern.

In the elevator, George decides to channel Cristina for Meredith if she channels Izzie for him, as their respective confidants had been very preoccupied lately. Meredith spills on Derek's infidelity, prompting George while channelling Cristina to say "McDreamy was doing the McNasty with McHottie? That McBastard." They then both decide to swear off relationships.

She later finds out that McHottie is actually Derek's sister. Nancy deliberately picks on Meredith, leading Izzie to call her McBitchy. Derek is unhappy that Nancy gets along very well with Addison and Mark. She later advises him that maybe he needs a little time alone, to sort things out. He subsequently tells Meredith that he does need a little time to himself and she agrees.

Izzie returns to the hospital and is once again assigned to Bailey. Bailey feels that Izzie should start afresh under another resident, but the Chief tells her that the other doctors doubt her judgments and abilities as a doctor and she should prove them wrong through Izzie. Izzie is ordered by Bailey to shadow Meredith, but not before telling her that she should not have any contact with any patients whatsoever and basically, be seen and not heard.

Izzie has difficulties re-integrating into hospital life as she realizes that many things have changed. When tending to a woman who severely burnt her hand a few days before taking her Bar exam, she brings Meredith the wrong gauze, not knowing that hospital protocols have changed. During lunch, she is stood up in the cafeteria, not knowing that the other interns have taken to having lunch in a sedated patient's room. There, she realizes that her friends have changed too. Cristina has become more distant and she is left out of Meredith and George's conversation.

Against Bailey's and Meredith's instructions, she confronts the burn patient, who she suspects deliberately burnt her hand to get out of taking her exam. Her hunch is right and she manages to convince the patient to undergo psychiatric evaluation by relating her own experience with failure. While leaving the hospital, she meets the Chief who tells her that Meredith gave her a good evaluation. He also welcomes her back to the hospital.

George and Addison have a patient with two uteruses, Noelle. She is also pregnant with one baby in each uterus and the babies have different due dates. Meanwhile, Alex is sent to run errands for Mark but is distracted by Addison's patient. He finds out that Greg, Noelle's fiancé, likes to talk sports to the babies.

Addison unwittingly exposes Noelle's infidelity to Greg, leading him to leave her. She goes into premature labor and requires an emergency C-section. George is unable to hold the second baby still while Addison delivers the first, putting mother and child in danger. Alex coaxes the baby to stop moving by commentating a boxing match to her. Later, Mark tells him that his future in plastics is over because he did not run Mark's errand for him.

Greg eventually reconciles with Noelle. George becomes motivated by Greg's commitment to Noelle and decides that he wants to commit to Callie. She tells him that she is tired of him chasing her unless he is ready to catch her.

Cristina takes it upon herself to protect Burke's secret by writing all his operations on the OR board. She deliberately schedules his operations in theaters without galleries and prevents other residents from scrubbing in. George and Alex feel that she is abusing her power.

Cristina schedules Burke to do a rare and highly complicated 'humpty dumpty' surgery, where the patient's heart is removed and the cardiac tumor is scraped out before putting it back in. Burke is unhappy that Cristina scheduled the operation that very day before telling him, but she allays his fears of not being able to pull it off. Bailey wants in on the surgery and writes her name on the OR board. Fearful that Bailey might expose Burke, Cristina erases Bailey's name off. This causes a hurt Bailey to think that Burke, like some of the doctors in the hospital, doubt her abilities as well. However, she later chances upon Cristina writing Burke's surgeries on the board and realises that Cristina was the one who erased her name.