Meanwhile, Lexie and Mark continue to work together but never seem to get their timing right, with Lexie acting hostile towards Mark when he wishes to reconcile, and Mark being caught sleeping with a flavor-of-the-day when Lexie wants to rekindle their romance. When Lexie and Mark both realize that they continue to harbor feelings for each other, however, they resume their relationship. Lexie nearly suffers another breakdown when the victims of a school shooting are sent to Seattle Grace Mercy West for treatment, which reminds her of her near-death experience during the shooting at the hospital. Mark comforts Lexie and the doctors ultimately manage to save all the victims of the shooting, after which Lexie tells Mark that she loves him. Lexie and Mark's happiness once again comes to a halt when she discovers that during their break-up, Mark had unintentionally impregnated Callie, and she ends their relationship once more because she is not ready for children.