A generous donation is offered to Seattle Grace by the parents of Arizona's 10-year-old patient. however, when his condition worsens, she finds herself in a conflict of interests. Meanwhile, Cristina tests her boundaries with Owen at the hospital, and adding insult to injury, Alex is left with all of Izzie's hospital bills to contend with.

When Isaac, the hospital lab tech, has an inoperable tumor wrapped around his spine, he turns to Dr. Derek Shepherd to do the impossible, and Derek tests the Chief's authority when Richard objects to moving forward with the risky surgery.

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 West and Seattle Grace residents defend their actions in an effort to save their jobs.

As Mercy West merges with Seattle Grace, battle lines are drawn between the two hospital's residents over the patients.

Thatcher is hospitalized with liver failure, and Meredith fights anger and guilt while deciding her responsibility. Sloan treats an octogenarian who wants an implant. Izzie's interference in Hunt's cancer case may have deadly consequences.