Grey's Anatomy: Season 5, Episode 13

5 - 13: Stairway to Heaven

Izzie is trying to figure out what Denny means by "I'm there for you". In the meantime, matters around the death-row patient get really rough while Bailey's patient continues to get worse, causing Bailey and Webber to cross the line. Lexie "breaks" Mark and Izzie comes to realize that she is sick.