There is no such thing as a dead letter. Until there is. Former enlistee Marilyn Moon was hoping for a quiet retirement after the end of The Last War. But when her colleague unexpectedly delivers a dead letter, Marilyn must go find her. Teaming up with the intrepid secretary Isabel and the disaster-prone Dr Simon, the trio will navigate a changed geography, killer kitchens, eerie neighbours, and the messy maths of space-time. As Marilyn learns more of Overworld's secrets, she begins to wonder - is this really the world that she fought for? A fast-paced sci-fi mystery, this 50s futurism novella will have fans of Terry Pratchett and Douglas Adams clamouring to learn more about the secrets of the Two Worlds.