Async Technologies discovers first stable entrance to the Backrooms in Level 0 — an abandoned office building in Ohio.

Project THRESHOLD initiated. Government-funded military-corporate alliance to map and exploit the Backrooms for resource extraction and weaponization.

First documented entity encounters. Initial expeditions suffer 72% casualty rate. Entities begin displaying adaptive intelligence.

Async establishes Level 4 Outpost. Backrooms begins showing signs of awareness — corridors rearrange in response to human activity.

The Backrooms starts producing Doppelgangers. Psychological warfare tactics deployed against expedition teams.

Project THRESHOLD reclassified. The Backrooms is no longer a place to be explored — it's an entity to be survived.

Events of THRESHOLD. Fireteam deployed to Level 4. The exit point has been compromised.