Ryan and Wick are trapped in a building after a chemical explosion. The gas affects them, making them get a little crazy. Even after they are rescued, they have trouble dealing with the possibility of future birth defects in their unborn children and the fact that Michael let the door close on them, trapping them inside the building.
Wick Lobo and Michael Bell welcome back their partner, Kathleen Ryan, after a stress-related leave of absence. They save men from a building that exploded. Ryan makes a heroic save of a man in a downed airplane that falls down a mountain. A woman that the team has visited before dies from being shot by her boyfriend.
Stations 27 and 77 are playing pranks on each other. A Russian woman's grandfather has chest pains. The squad rescues a teenager who falls while trying to hang a banner at his high school. Wick, Michael, and Ryan are caught in sniper fire while later answering a false alarm at the same high school. The shooter shows up at the station. Ryan deals with her ex-boyfriend.