Four new residents begin work at the busiest ER department in the United States.

Christa asks Neal to perform a surgery that will save a patient's reproductive future.

While working 36 consecutive hours, the doctors deal with a distraught mother of two sons who were in a devastating car accident.

Guthrie's estranged son joins the surgical staff and immediately clashes with Leanne.

Neal clashes with his neurosurgeon father over how to treat his gravely ill mother.

Leanne must decide whether to save a policeman, who helped her during her family's accident, or his shooter.