The Chaos Insurgency was originally a secret team organized by the O5 Council in 1924 to finish off dirty work without much trouble being pinpointed on the Foundation. However, in 1948, the Insurgency betrayed the Foundation by raiding one of their sites, killing many personnel and capturing multiple SCP's. The leader of the Chaos Insurgency is the Engine, who never shows their face to the public. The Engineer, however, serves under the Engine and frequently gets involved in raids.