

The Arctic waters off northern Norway, an icy international border where the military forces of NATO and the Soviet Union play a cat-and-mouse game of surveillance and counter-surveillance. These same waters are prime fishing grounds and the destination for deep-sea trawlers of many nations. One such trawler is the Caistor.
The Arctic waters off northern Norway, an icy international border where the military forces of NATO and the Soviet Union play a cat-and-mouse game of surveillance and counter-surveillance. These same waters are prime fishing grounds and the destination for deep-sea trawlers of many nations. One such trawler is the Caistor.
The British trawler Caistor has disappeared in the Barents Sea. Martin Taylor, son of the Chief Engineer, waits for news in the ship's home port. After the official search is abandoned, a private expedition to Norway is being organised by Tom Silvers, brother of one of the crew, but both British and Soviet Intelligence are determined to suppress public anxiety. As the official inquiry is announced, a lifebuoy is found by a Norwegian fisherman...