Derek and Meredith work with Zola on taking her first steps. Meanwhile at the hospital, the doctors work on separating Siamese twins, Andy and Brandy. The doctors split up in to two teams. Ben asks Bailey to move in with him. Arizona is very tense, making the doctors feel uncomfortable. Karev freaks out and Webber ends up taking the stealing the procedure from him. Baily is very hesitant and she goes to find Meredith for her to act a a buffer between them.
Cristina walks in while Teddy is operating. Teddy asks Cristina to explain, in detail, the procedure of Henry's surgery. While Cristina explains, April gets uncomfortable. Teddy asks Cristina to repeat the details of the surgery. Teddy slams Cristina with questions about Henry's surgeon, questioning every decision made. After all of this, Teddy breaks down and cries. Cristina tells her it's not her fault.
The doctors successfully separate the twins. Brandy had to stay int he surgery room to continue surgery. Brandy's kidney fails and the doctors bring in the healthy twin and do a kidney transplant. Meredith is in the OR with Bailey and Ben, where Ben continues to try to convince Bailey to move in with him. Baily finally tells Ben that she doesn't need any distractions - theyd ecide to take things slow.
When Lexie brings twins in to the the ICU, she overhears Mark saying something. She responds, then realizes he is on the cell phone with his new girlfriend. She runs way mortified. At the end of the episode, Zola takes her first steps.