On the forge world of Urdesh, an Imperial Guardsman recounts his near-death experience at the hands of an infilitrating force of Chaos soldiers. It started as just another midnight rotation for Cawkus, trooper, second class of the 50th Urdesh Regular, guarding Munitorum supplies at Depot 686 during a months-long siege. Retrace his footsteps as he recounts the events of that fateful night and uncovers a conspiracy that could strike at the heart of the city. It's a sneaky little story set in the build-up to one of the pivotal battles of the Sabbat Worlds Crusade, and shows the insidious nature of the servants of Chaos, and the danger they pose to the unity of the Imperial forces.