Pearl Harbor, ill-prepared and unknowing, is attacked by the Japanese.  Shortly afterwards, Captain  Rockwell Torrey is ordered to lead several U.S. Navy vessels against the enemy.  The mission ends in disaster, and upon his return to base, Torrey is assigned to a desk job.

He becomes attracted to nurse Maggie Haynes, who informs him that his son, Jere, whom he has not seen in the years since he was divorced from his wife, is an ensign on the island.  Jere, an opportunistic, callow youth with only contempt for his father, has plans for obtaining an appointment on the staff of the weak and indecisive Admiral Broderick.

Meanwhile, Torrey's temperamental executive officer, Eddington, has learned that his unfaithful wife was killed in a car crash during the attack.  As retaliatory naval operations are being set into motion, Torrey's true value is recognized by his superiors, and he is promoted to Rear Admiral.

Broderick has been unable to accomplish the spearhead mission of capturing several key islands, and Torrey is assigned to the task.  Participating in the operation are Eddington, Maggie, and Jere.  On Gavabutu Island, springboard for the attack, Torrey launches a successful foray, and boosts morale among his troops.  He thus wins the respect of Jere, who asks to be transferred back to his PT boat.

Meanwhile, Eddington, tormented by the memory of his wife's infidelity, drunkenly rapes Jere's girl friend, Annalee, at a beach party.  Annalee commits suicide, and Torrey breaks the news to Jere, thereby cementing the bond between them.  To redeem himself, Eddington undertakes an unauthorized "certain death" reconnaissance mission, and before he is shot down, he radios the exact size and location of the enemy force which is moving to intercept the U.S. invasion group.

In the great sea battle that ensues, the American force is largely destroyed, but the Japanese retreat in confusion.  Among those killed is Jere.  Torrey, badly wounded, returns home to recuperate in Maggie's care.  He is assured, however, that he will soon be back in action to command a new task force in the war against Japan.