Sealed Cargo

Captain Pat Banyon unloads his catch in Gloucester, Massachusetts, and reluctantly agrees to transport Margaret McLean to Trabo, Newfoundland. With a shorthanded crew, he hires Danish sailor Konrad and sets sail for the Grand Banks during wartime. The voyage begins under a cloud of caution as Banyon secures his crew and responsibilities.

Onboard, Konrad and Holger join the voyage, unfamiliar to Banyon. Tension rises as Banyon realizes he knows all his crew except these two, heightening his suspicion of loyalty. Holger reports that the radio has been sabotaged, fueling fears that a German agent may be aboard.

In dense fog at night they hear distant gunfire and discover the Den Magre Kvinde, a Danish ship, damaged as if shelled after a storm. Aboard, Skalder claims the crew deserted after a storm and that a U-boat attacked him; the Daniel Webster tows the Kvinde toward Trabo.

Konrad and Banyon secretly search Kvinde's hold and uncover a hidden chamber filled with torpedoes, revealing that the ship is covertly resupplying U-boats. They realize Skalder is part of a covert operation to support wolfpacks.

They watch Holger enter the hold and use a radio to signal the German fleet, unobserved by Skalder's crew. Before they can alert authorities, Skalder's men arrive by boat, and the incident is momentarily brushed off. Skalder plans to resupply U-boats at Trabo.

A Canadian flying boat lands in the harbor and an officer inspects Skalder's papers, finding nothing wrong. He informs Skalder that a corvette will inspect the cargo the next day. Banyon offers to leave one Danish crewman as a witness to root out Holger without arousing suspicion.

Banyon sails out of port with the rest of the crew while one man remains aboard to signal the nearest radio station and the others take fishing dories back. That night, he sets up an ambush to prevent the Germans from seizing villagers.

The German party attempting to seize villagers is wiped out in the ambush; the crew then sets fire to the Kvinde to destroy evidence and cover their escape. Margaret is freed from her hostage position as the chaos unfolds.

Skalder claims the ship is set to explode in twenty minutes, but Banyon suspects it is a ruse. He instead drives the Kvinde out to sea to keep the danger away from the village.

Two U-boats approach seeking supplies as Skalder wields a gun and wounds Konrad; Skalder is killed in the confrontation. A third U-boat surfaces, forcing Konrad and Banyon to escape by boat under heavy fire.

Banyon and another man help Konrad into a small boat and row away as gunfire erupts from the German vessels. The Kvinde explodes and a massive wave swamps the submarines, sinking them.

With Margaret safe and the German threat eliminated, the Daniel Webster's wartime mission ends in a display of courage and loyalty. The tense rescue underscores how civilians and sailors triumphed over espionage and piracy on the Atlantic.