When Izzie has a mental collapse after Denny's death, Izzie and Christina turn to Meredith to try and make it better for her. Callie tries to cope with George not returning the three word sentiment she said to him. Meanwhile, back at the hospital, Alex and Addison deal with a baby left in a garbage can at a local high school, Richard receives and ultimatum from his wife, and Derrick and George are quarantined in the locker room due to a patient suspected of having the plague.