A letter confirming the death of Mark Greene is delivered to the ER. While the tragic news sinks in, a grieving Carter (Noah Wyle) confronts Abby (Maura Tierney), and Weaver (Laura Innes) begins to worry about her own health -- and her future life outside of medicine. And having resolved the problems with Chloe and Suzy in New York, Lewis (Sherry Stringfield) prepares to return to Chicago. ~ Hal Erickson, Rovi