After pulling a double shift, Mario risks his own life when he follows Willis to a construction site where two brothers are trapped on a crane 300 feet above the ground. Also, Leanne treats the wife of an orthopedist from Angels Memorial who is brought into the ER with mysterious injuries.

The doctors work with the Center for Disease Control and Prevention to find an antidote to the deadly viral outbreak at Angels Memorial. Also, Leanne makes a life-changing decision, and Jesse welcomes a new batch of residents.