Owen has PTSD (Post Traumatic Stress Disorder) from his time in the war. One morning, Cristina wakes to Owen choking the life out of her. Owen is trapped in some sort of nightmare triggered by the spinning blades of Cristina's ceiling fan. She frantically tries to break free, but Owen is too strong. Callie hears the commotion and rushes into the room. Only then does Owen break his grip. Realizing what he has done and riddled with guilt, Owen can only pace and apologize. Crisitna goes to comfort the man she loves and tells him it'll be okay.