Benton pulls a 48-hour shift and refuses to sleep, despite Hicks's orders, which later proves disastrous for his mother. A doctor spends the entire day studying the ER as a model for a new hospital, and offers Susan a job; he turns out to be a psych patient who wandered downstairs. Jenn tells Mark she wants a separation. Doug treats an abused young girl, and Carol receives bad news about her attempt to foster Tatiana.

A new Chief shakes up the ER and is impressed with Susan. Mark remains deeply affected by the loss of a patient. Benton begins to realize his mother's future is not bright, and clashes with Tag regarding her hospital stay. Carter and Deb experience the strangeness brought on by the full moon coinciding with the naturally heavy Saturday night traffic