Based on the award-winning documentary of the same name, this medical drama follows the staff in the nation's busiest emergency room as they cope with a staggering influx of patients, which can outweigh their limited resources, resulting in a condition known as code black. Residency Director Dr Leanne Rorish - who is known for her success with high-risk procedures in the trauma area - leads first-year residents Christa, Malaya, Mario and Angus. Senior nurse Jesse Sallander manages the residents and serves as Leanne's confidant, with doctors Neal Hudson and Rollie Guthrie rounding out the group. Together the doctors and nurses race to save lives in an overwhelmed system.