Things were starting to turn for Lexie; Mark even confessed that he still loved her. That's when tragedy in the form of violence invaded Seattle Grace. A gunman entered the hospital and started shooting up the place. Almost anyone was fair game for the shooter, but one of the main targets was Lexie. Lexie and Mark discover that Alex was hit while on their way to find a safe place to hide. They had to act fast to save his life and performed surgery on him in a conference room. The incident ended only after the shooter committed suicide. Lexie tried to move on after the incident, but Mark had to admit her to the psych ward after she had a nervous breakdown during one of her shifts.