Meredith experiences another immense trauma after the hospital is put under a lockdown from an active mass-shooter seeking revenge against Derek. Meredith offers her own life in exchange for his and miscarries her baby during the crisis. She goes through this traumatic experience with Cristina, who operates on Derek while threatened at gunpoint. Meredith hides her loss and the trauma psychiatrist refuses to clear neither Cristina nor Meredith for their return to surgery. Meredith is able to work through her issues and become cleared, but Cristina remains deeply traumatized. Meredith covers for and supports her friend through her dark time, but is ultimately unable to fully help her return to surgery.