Capt. Matthew Garth (Charleton Heston) is a Navy fighter pilot who is reassigned to the Magic decoding department when he is badly injured during the attack on Pearl Harbor. Together with the head of the department, Cmdr. Joseph Rochefort (Hal Holbrook), they discover the Japanese plans to attack Midway Island and to ambush the remaining units of the crippled Pacific Fleet. As Adm. Chester W. Nimitz (Henry Fonda) makes plans to reverse the surprise and push the Japanese back from their offensive, Garth has to deal with his son Thomas (Edward Albert), now an ensign in his former squadron and in love with a Japanese American woman awaiting transport to the US internment camps.