Izzie then escapes to the faux seaside with Denny and stares at the "sky" with tears in her eyes until she realizes someone is calling her name.
George shows up in response to a page -- remember, these two used to be friends and George used to get more than two lines an episode? She still doesn't know what to do and figures she's dying either way, and asks George to tell her what to do. George, however, has the first calm and logical response to her plea: she knows what to do. She argues this but he points out that she's scared, and that's the only reason she's waffling, but that she made the decision back when she decided to fight the cancer in the first place. He tells her to look at how far she's come, to be a great surgeon and teacher (albeit with mania and drastic mood swings, only some of which can be explained away by the cancer) and then puts his arm around her. She leans into him and cries, in a scene that reminds me of how I liked when these two were really just best friends lo those many seasons ago, and he tells her, "You know exactly what you have to do."
Derek is reading and furrowing his brow like a champ when Mere and Izzie walk in and Izzie announces that he can do the surgery. He nods but can tell that something else is coming so he doesn't say anything and Izzie goes on to say she doesn't want to end up a vegetable. Mere tries to assure her this won't happen but Izzie cuts her off and says that she doesn't want to be on a ventilator and so she's signing a DNR. The look on Mere's face says that Izzie didn't tell her this before, and Derek finally looks more concerned than cocky.
She said that she wanted the surgery right away and she wasn't kidding -- Alex is walking next to her as they wheel her to the OR, and he begs for her to change her mind about the DNR. He's panicked and reminds her how nuts she went when Denny did the same thing, asking if she wants him cutting LVAD wires and ruining his career, because dammit, he'll do that. I kind of can't care about this whole argument, because Izzie's comeback is that she just didn't understand when Denny did it, but now she does -- so I feel like maybe she should have a little bit more sympathy for Alex for not understanding. On the flip side, Alex is a doctor and knows the consequences and should probably try harder to understand, because I think he's fully capable. She then tells him that where his eyes should be, she sees white sandy beaches, and there is an ocean behind his head with ghosts (again with the bullshit plural) wandering in and out, and she can't live like this. She pleads with him to not do anything crazy, and if things go wrong, to just let her go. Alex sniffles with tears in his eyes and Mere just stares at the floor as Izzie asks Alex to kiss her. He does, and they wheel her away. Before Meredith and Derek follow them in, Mere admits that she always thought it would be her that got Alzheimer's and forgot everyone. She then tells him, "Let's go to City Hall tomorrow. I don't want to spend another day not being married to you." He agrees and they kiss as Izzie is wheeled away.