Acolytes of Darkness is the second graphic novel based on the Agent 13 novels for TSR's Top Secret/S.I. espionage game. The plot of this book is loosely based on the story with the same name, which was contained in the first of the "Double Agent" novel trilogy. The timeline has moved forward two years to 1939, and the eponymous anonymous character fights against a new threat from the evil conspiracy who raised him and trained him in their ancient Lemurian arts. The ancient leader of this Brotherhood is marshaling his forces to renew his immortal life, and must be stopped.

This comic also includes a board game ("The Pursuit of Itsu") with a map and counters, and Top Secret/S.I. character writups for several NPCs.