The ESM-1 Breakglass is a single-use emergency SMG stored in a sealed wall-mounted case alongside fire extinguishers and first-aid kits in corporate facilities, orbital stations, and government buildings. The weapon is factory-loaded with a sealed 30-round magazine of 9mm frangible ammunition and cannot be reloaded — once the magazine is empty, the weapon is spent. The case is sealed with a tamper-evident breakaway panel and alarmed to notify security when opened.

The Breakglass requires no training to operate. The sealed case contains pictographic instructions, the weapon has a single control (safety/fire selector), and the BCI-compatible grip provides basic aim-assist to anyone with even a rudimentary neural interface. The weapon is brightly colored in emergency orange with reflective strips, ensuring it is never mistaken for anything other than what it is.

Crucible designed the Breakglass for catastrophic scenarios where security has been overwhelmed and untrained personnel need immediate access to a firearm. At Φ200 per unit installed, facilities order them by the hundreds. The weapons are inspected annually and replaced every five years. Most are never used. The ones that are used tend to generate stories worth telling.