Previously on Grey's Anatomy, if Derek signs the divorce papers, Addie will leave. She won't leave if she thinks there's the tiniest of chances he might want her back. Alex failed his boards and if he fails them again, he won't be a surgeon. He then won't let Izzie kiss him. Cristina and Burke fought, then he held her in the hospital. It's all been very dramatic.
There's a shot of some amazing lightning over the Seattle skyline to back Meredith's opening VO: "Pain comes in all forms." Izzie gets home from her date with Alex, the one that started with no kiss. She gives him some crap about how it was the "best date ever," until he can break in and say he had a good time. But then he dodges another kiss, nicely bookending Izzie's evening. VO: "The small twinge, a bit of soreness, the random pain. The normal pains we live with every day." She exclaims, "Seriously?! Seriously!" before slamming the door in his deserving face, and stomps up to George's room where she wakes him up so he can scooch over and she can get into bed and bitch over his protests that he wants to sleep.