The gunman incident on "Grey's Anatomy" is still very much alive in some people's mind. Newlywed Cristina experiences post-traumatic stress disorder in the midst of an operation, falling onto the floor and unable to move her body.

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 and Bailey refuses to let Alex operate until he agrees to have the bullet in his chest removed.

"Shock to the System" airs September 30 on ABC.

Star Jesse Williams indeed said the after effect will ripple through the first few episodes of season 7. "We really deal with the trauma of it all, and everybody has to essentially try out again and prove that they're worthy, that we're all worthy of going back into surgery," Williams told UsMagazine. "We have to go back and put people's lives in our hands, literally."