Grandma Got Run Over By a Reindeer

S2 E12: A young boy needs a heart transplant but doesn't seem to want it, and his treatment causes Burke and Yang to have philosophical differences. Meanwhile, when the interns rally to help Alex prepare to re-take his exam, Meredith has to remind Izzie of the true spirit of the Christmas holiday; and despite a reconciliation with his wife, Derek isn't in a festive mood.