Callie and Arizona are dealing with their own emergency -- their young patient has blood all over his clothes and Arizona is freaked out. The kid actually seems totally fine, but it turns out something went wrong and Arizona had to unhook him from his artificial lung. Callie's not bothered and says they'll just go back in and hook him back up, but Arizona thinks that is too dangerous, and the two start to argue again which is super appropriate in front of the kid's mother. But Callie then notices his stats and points out to Arizona that they are crazy good, better than they've been in his life. They run a quick test and his lung function seems amazing, and Callie finally admits to the mom that he might not need a transplant now. His mom dissolves into a happy freakout and hugs Callie, and an ecstatic Arizona then hugs her too, joking that she might love her. It all seems totally natural on Arizona's part and just a happy reaction to a kid's life getting exponentially better, but during the hug Callie has a funny look on her face like she might have twinges of Feelings She Doesn't Understand.
Bailey's patient is confused and not really happy to hear that Bailey is no longer doing his surgery. She tries to stutter through an explanation but is getting nowhere and Alex finally steps in and tells him it's a huge upgrade for the Chief of Surgery to do his procedure, like going from a dependable Honda Civic to a Jaguar. I once saw a man driving down the freeway with flames shooting out of the bottom of his Jaguar, so for me personally this isn't the most confidence-inspiring example. Ellis then swoops in to introduce herself and fast-talks through lots of medical jargon as she tells him what is happening. This includes the fact that instead of using his jugular vein to create a graft like Bailey was going to do, she's going to use something else that will cause less scarring. She tells them it's nice to meet them, and swoops back out, leaving them gaping and no clearer than before about what is going on. Alex manages to catch Ellis at the door and asks if he can scrub in; she tells him she'd be happy to have him. After Ellis leaves, Bailey is looking at the guy's chart and seems very worried about something, so she excuses herself.
Cristina has been called down as the cardio consult to talk to Lexille, and she tells her that due to the massive amounts of coke she's done, she now needs a pacemaker. She then helpfully gives her a brochure that describes the procedure, and leaves. Jackson assumes that Lexille's got no health insurance and asks if there's anyone he can call to help her out, which is just a way for us to learn that her parents are both dead. He asks her how they died -- so he can get some medical history -- and she says her mom died from a stomach issue while her dad killed herself. I am not a Thatcher fan, but that's sad. Though not entirely unbelievable. She then chuckles kind of sadistically and admits she has a half-sister who actually works at the hospital. When Jackson finally realizes she's not kidding he asks her who it is but she won't tell him; she explains that they have never met and she's pretty sure her sister wouldn't (or shouldn't) want to meet her.