From the best seller by Tom Clancy
CIA analyst Jack Ryan stumbles onto something he cannot explain while analyzing spy photos of Russia's newest missle submarine, and he flys off to Washington to meet with high ranking officials in the agency.
Based on his estimation of the situation Ryan figures out that the commander of Red October is trying to defect, and he is assigned the responsibility to help make that happen.
It becomes more than Ryan expected as he is involved in a shootout with a KGB agent hidden inside the October's crew, becomes involved in an undersea naval engagement with another Russian sub, and ultimately has to out think and out manuver some of the best minds in two opposing navies