Overview
Tower of Evil, also known by the titles Horror on Snape Island and Beyond the Fog, is a 1972 British horror film directed by Jim O'Connolly.
Plot
The movie opens with a boat cruising through heavy fog, on a spooky night. The boat lands on a rocky island (Snape) and two older seamen go on shore. Soon they find a severed hand with a crab on it. After they see the male body it was attached to, they decide to go into the lighthouse to investigate. They find a female body with a severed head. They split up and find another murdered body. Then they find a live, young woman, Penny, hiding in a closet. Traumatized to an extreme, she stabs the older of the men who finds her to death. The other man (the captain) of the boat survives.
Next, she is being examined by doctors who talk about her state of shock and how she and her friends made it to Snape Island. After running tests they try to find out more of what happened. Penny starts to talk and remember how her friends arrived. She starts to scream as the flashbacks disturb her.
After hearing about this, a group of scientists decide to visit the Island. They know that the Island is loaded with gold and Phoenician treasures. A team of 5 men and 2 women sets out on the Sea Ghost, which is captained by the seaman who survived the opening scene.
From Wikipedia (CC BY-SA 4.0).