Remember Really Old Guy, in whose room the Fab Five would eat lunch all during their internship? He actually wakes up, and it turns out he knows everything about everyone. Too bad he doesn't actually blurt out all of the really horrifying stuff. He's decided he wants to die that day, but Izzie can't believe it will really happen. He tells her that George is never going to tell Callie about them, which was AWESOME, but unfortunately…well, let's get to that in a moment.

Cristina figures out from Meredith and Derek's awkwardness that they're sleeping together again, and is totally miffed that Meredith hasn't told her. So she decides to act really sad about the breakup with Burke in order to get Meredith to give her surgeries. And she wins a doozy -- a woman is in with cancer of the tongue, and George inadvertently spurs Mark and Richard into trying a cutting-edge surgery neither has done before so that she'll still be able to talk afterwards. In exchange, Meredith takes her interns to work in the ER. This means she has to work with Lexie, who finally blows up at Mere after a procedure and then goes running to volunteer in the clinic. When Bailey finds out what is going on, she gives Meredith a talking-to about working with and teaching her sister as she's supposed to. Lexie also lets it slip that she thinks Meredith hated her mother, so once the day is over, Meredith brings her the report on her mother's death and reviews it with her so she knows what happened, and also corrects her that she really liked her mom. In between all of her sister drama, she figures out that Cristina's faking it because she's mad about Meredith not confiding in her like usual. She offers to have them stay up all night, talking and crying, and finally the truth comes out. Cristina then tells her that she doesn't need to be taken care of, especially not by Meredith withholding things from her to try and protect her feelings.

Alex gets a new intern assigned to him, who happens to be a few decades older than he is. They take a patient in the clinic -- a boy whose mom thinks he is doing drugs. Norman, the intern, makes chatty friends with the mom, and that contributes to Alex almost missing the correct diagnosis. He's got tons of fluid building up in his brain and as Derek's been pulled into the tongue surgery to save the day, he gives Alex instructions on how to drain the fluid in THE MOST horrifying surgical procedure I think they've had in the history of this show in order to save the boy's life. Afterward, Bailey gives Alex a dressing-down about how he needs to control his interns, no matter what their age, and that the pecking order of the hospital saves lives. Realizing she's had her own problems with this, she goes to make amends with Callie, who has been hiding and doing paperwork all day, and they agree to work together in the future. Which then brings us back to Izzie and George. He finally tells Izzie that it's his job to tell Callie and to back off (yay!) since it's not an easy or quick thing to do. But as it turns out, when he gets home that night Callie tells him to just spit it out, and so he admits he slept with Izzie. (Boo!)