When a British spy-ship sinks off the Albanian coast, the superpowers search for the on-board ATAC system, which controls British Polaris nuclear submarines.  Britain sends James Bond to locate the device, which he discovers has already been stolen. Bond suspects Greek businessman Kristatos and infiltrates his organisation.  Melina Havelock, seeking revenge against Kristatos for her parents' murder, helps Bond.

Together with unlikely ally, Milos Columbo, 007 travels from the bottom of the ocean to the peak of a mountain to prevent the ATAC falling into enemy hands.