Teddy wonders why Cristina didn't take the wheel in surgery. Her answer is simple. April was already there. That's just what Teddy wanted to hear. Cristina's next assignment is to make a bucket list of every procedure she's ever wanted. Now that Cristina is a team player, Teddy will try to make all her surgical wishes come true.
Derek does a consult for a young girl who keeps seizing due to a non-cancerous tumor on her brain. Derek thinks he can remove the entire tumor by doing a risky procedure that's never been done before. The girl's mom wants the safer surgery that'll offer only a temporary solution. Derek doesn't want to do that. He wants to prove to the mom that his way is the best way.
Derek's test probe attempts on a mock brain do not go well. He just can't find a clean approach without causing major damage. Nothing works. Owen suggests some batting practice on the roof to clear their minds. Then Lexie suggests that Derek adjust his body during his swing. This little batting tip makes him realize that he must adjust his patient's head and not the probe for the surgery. When it comes to good ideas, this one's a home run.
It takes a couple of swings at the plate, but Derek and Lexie manage to remove the entire tumor. As you can imagine, the young girl's mom is overjoyed. In other news, Bailey is less than thrilled to learn that Meredith dug up Ellis Grey's old journals to discover why her clinical trial is failing. These two could be on their way to curing diabetes if they could just learn to work together. They will.