| Director | Dick Powell |
|---|---|
| Budget | $1.9 million |
During World War II the American USS Haynes is on patrol in the South Atlantic. Lieutenant Commander Murrell, a former Third Mate in the Merchant Marine and now an active-duty officer in the Naval Reserve, has recently taken command of the ship. He is still recovering from injuries sustained when his previous ship was sunk by a German U-boat, and he was left adrift for 21 days. The crew questions the new captain's fitness and ability. A nearby German U-boat is commanded by Kapitän zur See von Stolberg, a wily former World War I Unterseeboot skipper who resents fighting for a Nazi regime he detests.
The two vessels engage in a game of cat-and-mouse, and each captain must guess what his counterpart's next move will be. Murrell subjects von Stolberg's crew to hourly depth-charge attacks, trying to force him to surface where his ship is more vulnerable. Von Stolberg analyzes Murrell's predictable pattern of attacks and succeeds in torpedoing the Haynes. Murrell orders his fires set on the deck to make the damage look worse than it actually is, then abandon ship. He retains a skeleton crew to man the bridge, engine room, and one of the guns. Von Stolberg falls for the gambit and surfaces to fire another torpedo to finish Haynes off, but Murrell rams the U-boat with the bow of the Haynes before it can fire, riding up over its foredeck and becoming stuck. With his own vessel foundering, von Stolberg orders his crew to set scuttling charges and abandon ship, putting the Haynes in further peril.
Murrell, the last man aboard, is about to join his crew in the lifeboats when he spots von Stolberg standing on the conning tower of the U-boat. He refuses to abandon his mortally-wounded executive officer Oberleutnant zur See Heinie Schwaffer, who has been with him since "academy days". Murrell tosses a line to the submarine and rescues the pair. Lieutenant Ware returns in the captain's gig with a mixed party of American and German sailors, who race up the cargo nets to save the last survivors before the tangled vessels blow up.
After rescue by another U.S. Navy vessel, German seamen give Schwaffer a burial at sea with the Haynes crew respectfully attending. On the stern, Murrell offers von Stolberg a cigarette as an olive branch. Von Stolberg, bitter about losing his ship, over losing his good friend, and about what has become of his country, says "I should have died a dozen times over, Captain. This time, it was your fault." Murrell says "Fine, next time I won't throw you the rope." Von Stolberg chides back amicably, "Oh, I think you will."