Addison’s still hanging around Seattle Grace. She extends her visit to help Derek treat Jen, a pregnant woman who’s having severe complications after brain surgery.
Jen’s initial surgery goes well but then she crashes again. Addison has no choice but to deliver the baby. Now! Derek insists he can save Jen. There’s a tense stand-off in the OR. Addison appeals to Meredith, who has been assisting. She tells Derek it’s too late for Jen but they can still save the baby. The Chief arrives and gently tells Derek to let the woman go. He’s done all he can.
Alex, Addison and Derek break the news of Jen's death to her husband. He wants details but the only things a guilt-stricken Derek can say is, "I'm sorry." Jen’s anguished husband screams, "You killed her. You're a murderer!"