In April 1942, during World War II, in the Atlantic Ocean, German warships adopted the "wolf pack" tactics, causing heavy losses to the Allies. Captain Taylor (Matthew McConaughey) of the U.S. Navy was promised to be promoted to captain for his outstanding performance against the enemy, but he could not do so for some reason. At this time, the enemy suddenly came, and Taylor was ordered to board the S-33 Master-class submarine to perform a secret mission. The commander was Captain Mike (Bill Paxton), and Captain Hash (Harvey Keitel) and Major Coonan were also on the same trip. After investigation, a damaged German submarine U-571 was sending a distress signal. The mission of S-33 was to disguise itself as a German repair ship, using repairs as a cover, and obtain Germany's most advanced decoding equipment from U-571. However, since the S-33 had been in disrepair for a long time and its water tanks and other equipment had reached the end of their service life, it would be dangerous if it dived below 200 meters. However, in order to complete the mission, Taylor and his team still drove carefully and attacked the German warship. But at this time, the German torpedoes also approached U-571. Their lives were hanging by a thread, and their lives were uncertain...