The Hunt for Red October by Tom Clancy
The Soviet's most valuable ship - a new ballistic-missile submarine with their most trusted and skilled naval officer at the helm - is attempting to defect to the United States. It is high treason on an unprecedented scale, and the Soviet's mission is to seek and destroy her at any cost. If the U.S. fleet can locate the Red October and get her safely to port, it will be the intelligence coup of all time. But the submarine has a million square miles in which to hide and the deadly game of hide-and-seek is on.