During the Cold War, Marko Ramius, a Soviet Navy submarine commander, plans to defect to the United States with the Typhoon-class ballistic missile submarine Red October. It is equipped with a cutting-edge silent propulsion system, known as a "caterpillar drive", that makes audio detection by passive sonar extremely difficult and enables the submarine to sneak its way into American territorial waters and launch nuclear missiles with little to no warning. As the sub leaves the shipyard at Polyarny, Ramius kills his political officer to ensure that he will not interfere. Ramius was ordered to conduct military exercises with Soviet Alfa-class attack submarine V. K. Konovalov, commanded by his former student Viktor Tupolev, in order to test the effectiveness of the caterpillar drive. Instead, he plots a course for the North American coast, falsely informing the crew that they will be proceeding undetected all the way to Cuba. Before sailing, Ramius sends a letter to Admiral Yuri Padorin brazenly stating his intention to defect; the Soviet Northern Fleet then sails out to sink Red October under the pretext of a search and rescue mission.
Tokkyuu Shirei - Solbrain (Japan) [En by Aeon Genesis v1.01] (~Derecive Solbrain)