On a family vacation, Lisa tries on a new identity to fit in with the other kids at the beach. Jealous, Bart reveals her true nerdiness to the group.

Derek is still operating when he finds out about Meredith’s current situation. Meredith is freaking out about her situation. Webber and Bailey are dealing with medical health issues. Cristina and…

An explosive case arrives at the O.R. that might endanger all the lives of the people working there, which leads Dr. Burke to declare a “Code Black” for the hospital….