The night is black, with only burning buildings and searchlights to guide you. High-explosive bombs bring death with only a brief whistle as warning. Everyone talks about the threat of invasion, or how they miss having bellies full of real food. You sing songs and huddle with those you love to try to keep the darkness and fear away. But there are far stranger threats in that darkness than German bombs: explosions release twisted forms from their forgotten prisons, inhuman scavengers are drawn by the carnage to feast; and opportunistic cults use the chaos of war to obscure their sinister plans. War has come to London and to Cthulhu Britannica, bringing unimaginable horrors with it! No air raid shelter or gas mask will save you now! Designed to work with both the World War Cthulhu and Cthulhu Britannica lines, this supplement brings the horrors of war and the Mythos to London in the 1940s. It includes rules for creating wartime characters, as well as background for what life was like in London during the Blitz and what threats might lurk in the blackout.