CIA Agent Jack Ryan is appointed acting CIA Deputy Director of Intelligence when his mentor, Admiral James Greer becomes gravely ill. His first assignment is to investigate the murder of one of the president's friends, a prominent U.S. businessman with secret ties to Colombian drug cartels. Caught in the crossfire, Ryan takes matters into his own hands.
A new technologically superior Soviet nuclear sub, the Red October, is heading the the United States coast under the command of Captian Ramius. The American government thinks Ramius is planning to attack. A lone CIA analyst has a different idea: he thinks Ramius is planning to defect, but he has only a few hours to find him and prove it. At the same time, the entire Russian naval and air commands are trying to find Ramius too.