The game is composed almost entirely of live-action full motion video, with sparse computer-generated graphics depicting external shots of the boat during torpedo attacks and atmospheric fly-bys.

The message reports that a stolen Libyan diesel sub has exited the Mediterranean Sea, possibly heading into Idaho's area of operations.

The rogue Kilo-class sub uses this tactic to launch a torpedo attack on the Idaho by pretending to be an allied Los Angeles-class sub, USS Biloxi.

After escaping the initial battle, a radio consultation with an American carrier battle group commander confirms that there are no other allied submarines operating in the area, and that a second hostile sub, a Russian Akula-class attack boat that has also gone rogue, is approaching the area.

Taking advantage of the lull in combat before the Akula-class submarine comes into torpedo range, a search of Idaho's outer hull reveals an act of sabotage instigated by one of the crew working for the enemy.