England, Lancashire, June 1920. In the house with the red door lies the body of a woman who was beaten to death. Rumor has it that two years ago she painted this door before welcoming her husband back from the front. Meanwhile, in London, a man suffering from a mysterious illness first disappears, then just as suddenly appears. He cannot explain his recovery. Relatives allegedly searching for him give conflicting testimony. Inspector Ian Rutledge, involved in both cases and facing a wall of silence, must unravel both mysteries before bringing the ruthless killer to justice.