A Russian special-purpose missile submarine cruiser disappears without a trace during a secret mission in the Greenland Sea. The crew under the command of Viktor Voronin, whose older brother commanded the missing submarine, is sent to search for it. The sailors are tasked with finding the submarine by any means necessary and preventing the new secret weapon from falling into enemy hands. At the same time because of geological research at the polar station in northern waters awakens Kraken - a giant monster, able to merge with the underwater darkness, possessing high intelligence. It is this monster that the sailors searching for the missing submarine will have to face.