Owen has a nightmare, triggered by the helicopter-like blades of Cristina's ceiling fan. She wakes to find Owen choking her. He only stops when Callie hears a commotion and comes in to check on her. Callie immediately calls Meredith, even though it's 3 a.m. Cristina insists she's fine, even though her neck is severely bruised. Owen can only sob, "I am so sorry. I don't know what happened." Cristina hugs him and tells him it's okay.
Derek shows up at Meredith's the next morning and wordlessly presents her with the ring. "No, not like this," Meredith says, closing the box. "Today's about Izzie," she tells him. "You have a gift and you can do this."
At the hospital, Meredith comments on the fact that Cristina is wearing a turtleneck and tells her, "You're not okay and your boyfriend's not okay."
To their surprise, Alex comes up and asks, "Is your boyfriend okay?" but he's talking about Derek, not Owen. "I was there for his carnage in the OR, remember? This isn't just any patient we're talking about today. This is Izzie."
George is so hurt that he was the last to hear about Izzie's illness that he asks Callie to assign him plenty of work that doesn't involve Izzie.
Miranda tells Meredith, Cristina and Alex that they need to be there as Izzie's friends, not as doctors, but when Izzie shoos them all away, none of them go back to visit her all day, even though they can think of nothing else. Bailey presents Izzie's case: They've lined up several treatments and surgeries for her over the next few weeks. Dr. Swender, who'll be administering her chemotherapy, tells Izzie, "The treatment will be aggressive and harsh. You should prepare yourself."
Richard suggests that Izzie might think about saving some eggs in case she wants to have babies later on. Richard informs Alex that frozen eggs have a better survival rate if they're fertilized. Alex quickly agrees, but he's too guilt-ridden about not having recognized Izzie's symptoms. "This isn't how Izzie and I were supposed to make a baby," he tells Meredith, but eventually he's able to present Richard with his "contribution."
Owen awaits the arrival of a patient trauma case by helicopter, and the helicopter blades, like the ceiling fan, clearly trigger an unpleasant memory, but he runs off before anything happens. Derek witnesses Owen's rooftop meltdown and advises him to get treatment for his post-traumatic stress disorder, but Owen refuses. Owen tells Cristina they have to stop seeing each other. "I know my limits. Let me decide what I can handle," she says. Meredith presses Cristina to leave Owen and Cristina insists that Owen's condition is no different than if he'd lost a leg.
Miranda quizzes Izzie on a medical procedure, saying she'll need to know it in the future. "You really think I'll be here a year from now?" Izzie asks and Miranda answers, "Yes, I do."
Arizona finds Callie in the chapel, wracked with guilt because she literally "wished Izzie Stevens dead for a year. What kind of person wishes someone would die?" Arizona asks if she's praying right now for Izzie to die and Callie says, "No, I'm praying for her to live." Callie finds George, who's furious that Izzie told him nothing was wrong every time he asked. "We are going to go pray for her," Callie insists. "One time you loved her enough to ruin our marriage. I know that you care if she lives or dies."
Derek preps for surgery, but he tells Meredith, "I'm not ready." He tells her he needs her to say yes, but she says she's not going anywhere.
Alex goes to talk to Izzie before her surgery, but he's too late. "It's a beautiful day to save lives," Derek says as he puts Izzie under. Izzie makes it through the first surgery just fine, but Miranda chews out her friends for not going to visit her. "Tomorrow, do better," she tells them.
When Richard wants to know why Derek and Meredith aren't out celebrating the success of the surgery, Derek tells Richard that she has turned him down twice. "Meredith believes in you," Richard replies.
Richard makes Meredith wait for the elevator and when the doors open, she sees why: A clean-shaven Derek is inside and the elevator is decorated with scans of all the surgeries they did together. He recounts the stages of their relationships as they played out during each case. Lastly, he shows her the post-op scan of Izzie's brain. "You got me into the OR," he tells her. "You put the rest of us to work because you've seen worse. You know we'll survive. You say you're dark and twisty, but that's not a weakness, it's a strength. It makes you who you are. I love you Meredith Grey, and I want to spend the rest of my life with you."
"And I want to spend the rest of my life with you," she says, and they kiss.
Owen and Cristina make love for the first time. Afterwards, she confesses, "I don't think I can handle this after all," she says. "I'm so, so sorry, but I'm lying here and I'm afraid to fall asleep." Owen turns to Derek for the help he offered earlier, and Derek starts with an MRI scan.
Meredith goes to Cristina's apartment to tell her, "I'm engaged."
"I broke up with Owen," Cristina says. Meredith crawls into bed beside her, just as Alex does with a groggy Izzie.