Owen reminds the teams that the surgery on the twins will last at least 18 hours, and each doctor is to get there at least 30 minutes before their procedure. With that, Arizona and Jackson begin the final practice run. She's really jumpy and keeps cutting off everything Jackson says and basically takes over every single step whether it is supposed to be hers or not. Richard and Alex are watching what's going on and Richard, who came in on his day off just to see this, mentions casually how wound up she is. Alex is helping out with the "flip" and he says he's ready, but as they watch Arizona's nitpicking Richard points out that she'll destroy everyone else's confidence that way. He then reminds Alex that if the flip goes wrong she will blame him and it will look really bad on his record, right before the boards and all. On cue, Alex is then up for the practice flip and the doubtful glance he shoots at Richard shows that Richard has done a good job gnawing away at Alex's confidence.
Out in the waiting area, Lexie is explaining to the extremely young parents why the flip is so important -- the babies will have open incisions that need to be kept sterile, they need to stay intubated, and the docs need to keep all of the various wires that are attached to them from getting tangled. Seeing that they don't really understand what most of that means (they obviously don't watch medical procedural shows every week) she compares it to changing a car battery while speeding down the freeway. She immediately realizes this is a rather insensitive metaphor since she is talking about their actual children, but the dad points out that this is the first thing he's really understood all day. The young mom, Gretchen, is extremely worried but Lexie assures them that the doctors have been practicing for weeks and have it down pat.
Back in the OR, though, the practiced choreography has dissolved into a shouting match between Arizona and Alex as they hopelessly tangle up the baby dolls and blame each other for Brandi and Andi, the twins, now suffering all sorts of damage from the botched flip. Owen just calls them back and has the other doctors move on with the next step of the surgery. Meredith leans over and points out unnecessarily to Alex that that was a disaster, but he argues that he's got this down and all would be fine if Arizona would just trust him. Bailey then comes in and calls Meredith away.