A new technologically-superior Soviet nuclear sub, the Red October, is heading for the U.S. coast under the command of Captain Marko 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 - because the entire Russian naval and air commands are trying to find him, too. The hunt is on!
When the president of Russia suddenly dies, a man whose politics are virtually unknown succeeds him. The change in political leaders sparks paranoia among American CIA officials, so CIA director Bill Cabot recruits a young analyst to supply insight and advice on the situation. Then the unthinkable happens: a nuclear bomb explodes in a U.S. city, and America is quick to blame the Russians.