疯狂的芭堤雅将军杜罗夫（米哈伊尔·戈尔沃伊 Mikhail Gorevoy 饰）预谋发动第三次世界大战，他制造了一场巨大的水域爆炸，致使附近的美军潜艇队遇袭。美国海军派出了海底经验丰富但名声寥寥的乔·格拉斯潜水艇船长（杰拉德·巴特勒 Gerard Butler 饰）率领潜艇队前去调查。A U.S. submarine, the USS Tampa Bay, vanishes while shadowing a Russian Akula-class submarine in the Arctic. Rear Admiral John Fisk sends a Virginia-class submarine, the USS Arkansas, under the command of newly-promoted and unorthodox Commander Joe Glass to investigate. At the same time, a Navy SEAL team under the command of Lieutenant Bill Beaman is sent in to discreetly observe a Russian naval base. When they arrive at the naval base, they witness defense minister Dmitri Durov conducting a coup d'etat and taking Russian President Zakarin prisoner, and swiftly realize that Durov intends to trigger a war..