The crowd outside Mark's room has grown to include Bailey and Alex, who has a bag slung over his should and is about to leave for Baltimore. Bailey takes the quiet moment to ask about her nickname -- does it command respect or strike fear in the hearts of residents? Richard admits that it does neither and finally says that the residents have noticed how "happy" she gets whenever Ben rolls into town. He then crosses his arms and refuses to divulge any more. After some pouting, Alex finally says that since he's about to actually walk out the door never to return, he's going to spill the beans. Richard and Avery furiously try to stop him but Alex declares that her nickname is "BCB" -- "Booty Call Bailey." She chokes but finally manages to thank him, though she refuses to look at him as he wishes them all goodbye.
Mere is waiting at the airport, nervously fidgeting with a book, when she sees Alex walk up the stairs and she runs over to confront him. She's rightfully offended that he wasn't even going to say goodbye to her, and won't let him change the subject when he asks why she is even there. He tells Mere that they will still be able to talk but Mere yells back at him that Cristina said the same thing but that it's not at all the same. More crucially, everything is different now, Mark is dying, and Mere seems barely able to handle everything. Alex, though, turns out to have his own issue in his massive survivor guilt. He tells Mere he can't hang around and keep being known as the guy who should have been on the plane. The fight escalates, and he finally yells that he's not going to stay just because Mere doesn't want to be alone and softens it only a little bit by adding that Hopkins won't wait for him forever. She glares at him and storms off and while he's standing there, someone bumps into him in their rush to another gate. Interestingly, that person is Owen though Owen seems to not realize that he just literally ran into Alex. Owen runs up to his gate and just barely makes it on his flight. So the question we are to ask is, where is he going? And the answer we are to assume is, to go see Cristina.
Derek and Callie are still waiting with Mark and finally, his vitals begin to drop. Outside, Ben has joined Bailey and as an alarm starts to ring he takes her hand. Mark is still while Derek sadly shakes his head and he and Callie each reach out and put one hand on each of Mark's shoulders, crying.
A totally touching home movie shows Mark rocking a teensy baby Sofia to sleep, grinning with pride as he snuggles her. He looks at the camera, smiles, and puts his finger to his lips. Dammit, show. You got something in my eye.