Cristina surprises Meredith and Derek by telling them that Erica has left Seattle Grace. Just then, one of Meredith's oldest friends, Sadie, arrives. "How good a friend can she be?" Cristina asks. She's never heard of Sadie.
Sadie says that the reason she went to medical school is because of Meredith, but she worked in a morgue which put a hold on her residency.
Izzie is hesitant to to go to work after having faced the man whose heart she took for Denny. When she enters the hospital, Denny is there waiting for her.
His ghost remains throughout the day. She sits with a man who has a "piggyback" heart transplant. The patient, a Navajo Indian, firmly believes that he is haunted by the girl whose heart he received. He wants it taken out of him; even if he dies as an outcome. He notices that Izzie is haunted by her ghost and tells her that he does not need anymore ghosts in the room.
When the girl's heart is removed, the man's heart beats on its own. They believe that he will no longer be haunted. He decides to burn the heart and Izzie decides to burn the sweater she made for Denny, which is her last possession of his.
Cristina sees scratches on Lexie's arm and thinks that she is a "cutter." Actually the cuts are from practicing techniques with the other interns.
Lexie tells the interns that they should shut down for a while, but Sadie thinks they should keep going. She says to Lexie, "You're only going to learn so much by being careful," and she takes off her shirt and cuts her shoulder. Then she asks who wants to stitch her up.
A homeless man, crushed in a dumpster and impaled on his leg, enters the hospital. He tells the doctors that he does not want to live if his leg cannot be saved. Owen tells Cristina the surgery is off.
Derek asks Callie to find a way to build the man some legs. She rebuilds his leg, but he dies on the table. Callie cries because she did her part, but she feels that everyone else let her down and in turn let the patient down. Mark comforts her.
Cristina finds out that the interns are practicing on each other and tells them to shut it down.
Izzie tells the ghost of Denny that she will always love him. However, after she burns his sweater and says "bye," he does not leave. She extends her hand out to him and can feel his heart beating. He assures her he is real and gives her a kiss.
Everyone is drinking their sorrows away at the bar, and outside, Owen sees Cristina upset that she lost her patient. He kisses her.