An almost impossible puzzle with supernatural trappings. In a remote house in the middle of Dartmoor six shadowy figures huddle around a small table for a seance. Tension rises as the spirits spell out a chilling message: ' Captain Trevelyan...dead...murder.' Is this black magic or simply a macabre joke? The only way to be certain is to locate Captain Trevelyan. Unfortunately his home is six miles away & with snow drifts blocking the roads someone will have to make the journey on foot...