Grey's Anatomy, Season 7, Episode 2 - Shock to the System

After weeks of concealing the fact she was pregnant and miscarried, Meredith at last tells Derek and is finally cleared to return to her surgical duties in the wake of the hospital shooting spree; Cristina experiences post-traumatic stress disorder in the midst of an operation; and Bailey refuses to let Alex operate until he agrees to have the bullet in his chest removed.