Cristina and Mere are trailing after Derek, Mere arguing that she is a better doctor than Cristina so should be the one on Derek's service. The fact that Cristina agrees with her is a sign of just how bad her mental state is right now. Derek just kind of ignores them until he gets a page, and when he sees his sister waiting for him he lets out a displeased groan. Mere is just surprised to learn there's yet another sister she hasn't met and Derek halfheartedly introduces them, though Amy corrects that her name is Amelia and Derek is the only one who can call her Amy. I had figured she was about 24 years old or so, but it turns out she's a neurosurgeon too so obviously she's got a few more years than that under her belt. She introduces her gift, Todd (though she calls him Tom) and it comes out that they just met on the plane. So he's more of a last-minute gift, then. Derek realizes that they totally hooked up on the plane and tries to stalk off, but Amy just points out that he is still a dude with a brain tumor. Derek isn't interested in getting involved and says Cristina will find them a doctor, so Mere runs after him and points out that he could at least take his sister for a coffee. Derek has absolutely no interest, much to Mere's surprise, but he seems to at least decide to take Todd as a patient and he has Cristina do the workup.
Richard seems to have an easier time treating actual patients while also being Chief, and he helps wheel a guy into the elevator. Alex is working with him but hangs back, and then makes an excuse to run off and get some lab results even though Richard yells after him that this is a higher priority. Mere offers to help but Richard orders her to the OR instead to help out April, who pops up just as the elevator doors close. April can't believe that Derek took Cristina to help him that day and stupidly starts to babble about what a mess she is, noting that she saw Cristina that morning, and did she spend the night? Wait, does this mean April lives in the house now? Honestly, don't Derek and Meredith want to live alone at some point? This isn't even the same as Mere's friends living in the house, this is just a new employee (who, by the way, presumably already lived in Seattle since Mercy West was also in the city). There isn't an explanation about the living situation; Mere just glares at April and warns her that she doesn't talk about Cristina and April should mind her own business. April's nose is bent out of shape and she promises to try and not be concerned about others' well-being in the future.