In April 1942, during World War II, German warships adopted "wolf pack" tactics in the Atlantic Ocean, causing heavy losses to the Allies. U.S. Navy Captain Taylor (Matthew McConaughey) was promised to be promoted to captain for his outstanding performance in resisting the enemy, but he could not do so for some reason. Suddenly, there was an enemy situation. Taylor was ordered to board the S-33 lord-class submarine to carry out a secret mission. The commander was Captain Mike (Bill Paxton), accompanied by Captain Hash (Harvey Keitel) and Major Coonan. After investigation, a damaged German submarine, U-571, was sending out a distress signal. The S-33's mission was to disguise itself as a German maintenance ship, use maintenance as cover, and obtain Germany's most advanced decoding equipment from the U-571. However, due to the long disrepair of the S-33, water tanks and other equipment have reached the service period, it may be dangerous to sneak below 200 meters. However, in order to complete the mission, Taylor and others still drove carefully and attacked the German warship. But at this time, the German torpedo also approached the U-571, and their lives were on the line....