Callie and Arizona continue to argue about having a baby, but they're interrupted by Mark, who's banging down the door: He needs their help with Sloan's baby. When they get back to the apartment, Teddy's already delivered the baby safely.
Mark is ecstatic to be a grandfather and Sloan reconsiders giving up her child. "Maybe we should keep him," she says. Arizona thinks it's a terrible idea, since Sloan has no idea what she's doing, and she and Callie butt heads over the best thing to do. "This baby needs parents, not an 18-year-old child and a father she met five minutes ago." Mark tells her, "This is my grandson. I'm not just going to turn him over to some strangers when I might have a chance at a family." Sloan's freakout when left alone with the baby helps make Arizona's case. Callie tells Mark, "She's a baby herself." Mark and Sloan finally decide that giving the baby up is the best thing, but we can see how hard it is for Mark.