Helena Montague, the heiress to a grand fortune, is mourning the recent death of her father. Feeling lonely at Chateau de Rouge, the large, ancestral mansion that she has just inherited, shes invited several old friends to come and stay with her for a while, to keep her company.
But being that it is a dark and stormy night, there are even some surprise visitors who arrive at the mansion, seeking shelter from the storm. Soon, the group realize that one member of their party is missing and that something horrible has occurred there.
Before the night is over, they find themselves solving a dark mystery, proving that one member of their group is a cold-blooded killer.