When a young woman inherits a magnificent Tudor mansion, she believes her days of financial struggle are over. But the Guest House at Hampton Court carries a dark reputation, having been shuttered for thirty years following a tragic death. As the ancient doors are finally forced open, a series of inexplicable and fatal heart attacks strikes those who cross the threshold, leading locals to whisper of an ancestral curse. Her struggle for happiness is further jeopardized by a ruthless aunt and a cunning former butler who plot to sever her engagement to a hardworking doctor. As the couple navigates the high-society circles of the Riviera and the snowy peaks of Switzerland, they remain unaware that they are being shadowed by a brilliant criminal lunatic known as the Chameleon. Possessed of a deadly secret poison from the East, he is determined to eliminate anyone he deems an intruder upon his rightful domain.