The heath hover mystery

One dark night, a mysterious stranger falls through the ice near the lonely house called Heath Hover. John Mervyn rescues him and gives him shelter, but the stranger is dead of undiscoverable causes in the morning. The investigation is still ongoing when Mervyn's niece Melian arrives for a long visit and catches the eye of Scotland Yard's finest, but none of them could predict the final scenes of the adventure in the wilds of northern India.