In the city of New Orleans, police officers, fire fighters, and emergency medical technicians working the overnight shift answer as many as a thousand emergency calls every night. Early in this shift, a fleet of police cars and ambulances respond to a report of a man discovered in the street bleeding from multiple gunshot wounds. EMT's Holly and Gavin work furiously to keep the victim alive, rushing him to the hospital, while police flood the neighborhood investigating the shooting and trying to prevent retaliation.

It's an emotional night on the Nightwatch in New Orleans as one EMS officer tells his partner that this is their last night on the job. Meanwhile, it's a tough night in a different way for the fire fighters as the group responds to a call about a truck on fire after a collision at a gas station. It's a night that serves as a reminder that the people of the Nightwatch aren't just there for their city--they're there for each other.

After a quiet beginning of the evening, multiple calls virtually explode across the radio at once--and the most alarming code heard is for "Officer Shot." The overwhelming response to that call leaves EMT's Titus and Dan to endure an agonizing wait for police backup at the scene of a stabbing at a birthday party. Meanwhile, fire fighters respond to the scene of a burning car.

Halloween provides a fitting backdrop to a night on the job that includes some chilling calls. Captain Kevin leads the fire fighters battling a blaze that's engulfed a house, and hopefully nothing more. Police officers Victor and Cedric hunt through a neighborhood in "the country" for a burglary suspect. And on the EMT Sprint Unit, Becca responds to a call she hoped to never get.

Police officers Victor and Lejon join a SWAT team operation hunting a homicide suspect. The fire department tries to save a man who fell into the Mississippi River. And for the EMT's, the calls tonight are as much about comforting victims as they are about saving them.

It's a full moon in New Orleans, and sure enough, all night long, the calls for the EMT's seem to get crazier and crazier: the victim of a machete hacking, the man whose finger is bitten off by a dog, the guy stabbed by a man dating his ex-wife. Meanwhile, two cops keep their perfect record of chasing down suspects in foot races intact, and a fire chief confronts his fear of rats.