In a soon-to-be-closed precinct in a desolate section of a Los Angeles ghetto, a skeleton crew of officers is preparing to move operations to a new location. Lieutenant Ethan Bishop, assigned to oversee the precinct's last night, anticipates a routine shift. However, unbeknownst to him and his limited staff, the night will challenge their notions of duty and survival. The precinct becomes a beacon for violence when a father, seeking revenge for his daughter's murder, accidentally leads a street gang right to their doorstep. With the building under siege, the line between law enforcers and lawbreakers blurs as both sides fight for their lives.

Among the precinct's unexpected defenders are two prisoners, Napoleon Wilson, a convicted murderer with a cryptic past, and Wells, a chatty petty criminal being transferred through the precinct. As the gang lays relentless siege, using silencers to avoid attracting outside attention, those inside must band together to fend off the attackers. With limited weapons and no external communications, the makeshift defenders must devise a plan to survive the night against an enemy that vastly outnumbers them. The siege tests the limits of their endurance and pushes them to make desperate decisions. In the crucible of violence, unexpected alliances are formed, and heroes emerge in the most unlikely of individuals.