In October 2002, a Chechen commando unit seized the Dubrovka theater in Moscow during a sold-out performance of the musical Nord-Ost, taking roughly 850 audience members, cast, and staff hostage. The film reconstructs the three-day siege largely through footage shot from inside the building, much of it captured by the hostage-takers themselves and by hostages using their phones, along with news broadcasts and negotiation recordings. Survivors describe the explosives strapped to female bombers seated among the crowd, the failed attempts at negotiation, and the moment Russian special forces pumped an unidentified gas through the ventilation system before storming the building. That gas killed most of the roughly 130 hostages who died, and the film presses on the Russian government's refusal to disclose what it used or how to treat it, leaving doctors treating survivors blind. Interviews with former hostages, security officials, and journalists lay out a siege that ended the immediate crisis while raising questions about the raid's real cost that were never answered.