The moon hung heavy, a silver pendulum over the manor's brooding silhouette. Inside, the clock struck midnight; its chime echo faded last. Crystal glasses clinked, guests murmured, unaware of the impending doom. A scream shattered the harmony, piercing as a knife through the din. Silence followed, abrupt and total, save for a distant door slamming shut. Footsteps approached, hesitant yet determined, pausing at the grand library's entrance. There, sprawled across the oriental rug, lay Lord Montgomery, lifeless eyes staring towards the ceiling. His throat bore a crimson smile, a gruesome second mouth. The guests gathered, a tableau of shock and horror framed by bookshelves. Among them stood Eleanor, his wife, her gown a stark contrast to the growing scarlet pool. Detective Inspector Lestrade arrived, sharp eyes taking in every detail, every face frozen in disbelief. "No one leaves," he commanded, sealing their fates within the room of secrets.