When Sybil Delafield's coach to Croft Towers was robbed by highwaymen, she should have realized that being companion to old Mrs. Chalcroft would be no ordinary job. After she arrives, Mrs. Chalcroft sneaks into her room in the dark of night, imploring her to relay messages to town that must stay hidden from the rest of the family. Who exactly is she working for and what do the messages contain? When Sybil's fellow passengers on the robbed coach are murdered, her questions take on a new urgency. The only person she can rely on is Mrs. Chalcroft's godson . . . but Mr. Sinclair's charm also conceals a double life.