The plot features a farewell party for one of the principal characters, Dr. John Carter, and multiple trauma victims of a porch collapse event.
County General then stops accepting trauma patients after further problems with the sewer pipes in the hospital leaves them with only one operating room, coupled with the fact that the majority of the ER staff is at Carter's party.
Barnett uses the radio to call County and demands that Abby reopen the ER, otherwise the five critical patients would probably not make it to the hospital.
The presentation features past ER doctors, including Dr. Doug Ross (George Clooney), Dr. Mark Greene (Anthony Edwards), and Dr. Peter Benton (Eriq La Salle).
Before he leaves he stops by to see Ray, Neela and Abby and shares the letter he wrote to himself as an intern under Dr. Greene, that had sat in his locker until this point.
As Carter is leaving the hospital for the last time, Dr. Greene and Dr. Benton (his primary mentors) and Nurse Carol Hathaway are heard in voice-overs.
This is Scott Grimes' final episode before becoming a regular cast member in season 12, playing character Archie Morris.