Once they are in the scrub room, Cristina throws up her hands in frustration and cries that she is officially giving up since she has no idea what Teddy is trying to teach her. Teddy tells her to make a list, but that strange request does nothing to ease Cristina's confusion and frustration. She starts to rant but Teddy cuts her off and tells her to make a list of every amazing surgery she has ever dreamed of doing and that she'll then try to make those things happen. Cristina seems to think this is about the least funny joke she's ever heard but Teddy is serious and tells her that she finally graduated from the school of unselfish surgeoning, and this is her present. Because Teddy saw that Cristina is finally willing to work on a team and put the patient first, Cristina now gets to make a bucket list of sorts and Teddy will try to be her fairy godsurgeon and make it all come true. She leaves, and Cristina finally allows herself to smile.
Kicky music accompanies us into the mouse lab, where Bailey catches Mere looking at something under a microscope and begins to lose her shit. Mere yells back at her to hang on a second just while she looks at something, and then exclaims joyously that the cell she's looking at survived. Bailey is confused enough that she asks what Mere is talking about, so Mere explains that she went back to look at her mother's original hypothesis and realized that there was a flaw in it because in one particular way mouse cells react different than human cells and that's why the device is failing. She then adds a wee bit smugly that she marked the page for Bailey, and then leaves as Bailey glares after her. But she looks under the microscope, and lo and behold sees a happy, healthy cell. (Well, I assume. I think she saw a bunch of red and white blobby stuff through the microscope.)
Derek goes to talk to Mrs. B and her sleeping daughter and when he tells her that the tumor is all gone, she doesn't hear anything else he says and just jumps up him to hug him. The doctors beam at her and at their good luck in surgery.
Carl wakes up to see his hand in all sorts of crazy traction but nonetheless, it's a hand with five original fingers. Callie explains what she did and when he asks tells him that it should work just fine, though after some more surgery and a whole lot of physical therapy. He's beside himself and thanks her sincerely, then turns to his wife and brags that he told her Callie was an artist. I think Callie has earned the happy and proud grin on her face.