We open on-board a ship at sea, a large explosion rocks her. Has the engine blown or…? Suddenly the crew spots a torpedo heading straight for them. They brace for impact and survive the assault. A submarine suddenly rises and machine gun opens fire on the crew, killing every one on board. This is not the first incident, 18 Ships have been sunk in the last 3 month and people are loosing confidence in the sea.
Lamont Cranston – The Shadow – reads the news of the sinking and sets out to get to the bottom of the mysteries. The Shadow pays a visit to Mr Joseph Hart – expert submarine designer – and begins to uncover a sinister plot which threatens the life’s of all who sail on the seven seas.