Grey's Anatomy: Season 5, Episode 17

5 - 17: I Will Follow You Into the Dark

Izzie walks the interns through diagnosing Patient X after receiving her troubling test results. Bailey and Meredith perform a surgery where they remove a woman's stomach to protect her from a very invasive form of stomach cancer that runs in her family. Hunt and Karev treat a high school marching band player with seizures. Shepherd has to come to grips with killing one of his patients. Cristina receives some disturbing news from one of her colleagues.