Young Jefferson Carruthers has been assigned to a new post as an Indian agent. He and his wife board the Enterprise to travel to their new home. Also on board is Vance Muldoon, who plans to offer Carruthers money if he will smuggle liquor to the Indians.

Prisoner Paul Drake is being returned to custody by a prison guard. Because Drake has already tricked him once, the guard shackles his prisoner to a deckhouse on the Enterprise.

The Enterprise is badly in need of repairs and Holden has got to accept Nick Logan's offer. He will repair the boat, if afterward, he and his partner can use it.

The Enterprise steams upriver with a cargo of arms and recruits for the Fort Union outpost. At Akins Landing, Grey Holden is told by Homer Atkins that the Sioux have been watching the boat and are planning an uprising.

The Enterprise, tied up overnight, is boarded and highjacked by a vicious crew, who kill the three men left to guard the boat. Captain Grey Holden and Ben Fraser return to the scene in time to see their craft heading down the river. They set out overland to head her off.

Actress Lorna Langton wants to charter the Enterprise and a skeleton crew for a trip to St. Louis. The actress has been told that her young son, kidnapped some years before, is being held in another town.

John Jenkins has placed a large down payment on land owned by three ruthless farmers. Jenkins is planning to deliver a shipment of peaches, via the Enterprise, to Cincinnati, as a final payment for the land. But the farmers plot to block the boat so the shipment of peaches will be spoiled.

Ansel Torgin hires the Enterprise for his daughter's wedding. Captain Grey Holden recognizes the bridegroom as a drifter he once threw off his riverboat.

Lt. Perry Quinn, an officer in Sam Houston's Texas Army, hires the Enterprise to deliver a cargo of lead down river. Captain Grey Holden is warned that Santa Ana's agents may try to sabotage the shipment.

The crew of the Enterprise planned a big night on the town. But when they dock, they find the place completely deserted, except for three new graves.

Wealthy Roger Mowbray's marriage is threatened when an old sweetheart intimates that Roger married for money. Because he really loves his wife, Roger is doubly upset to discover that his father seems to be involved in the scheme to break up the marriage.

Dan Duryea steps into the leading role for the first of two episodes.

Riverboat pilot John Murrell plans to hijack a shipment from rival pilot Dan Simpson. Murrell arranges to have Lela Candida take a job on Simpson's boat as a dancing girl, so that she can signal his raiders when to attack.

Anthony Lorrimer charters the Enterprise to deliver a cargo of farm machinery to his thriving community of Lorrimer City. Captain Grey Holden is unaware that the cargo is actually arms and ammunition.

Dan Duryea has the leading role in the second of two episodes.

Otto Justin, dealer in wild animals, is escorting a shipment of his captured beasts to St. Louis aboard the Enterprise. Widow Abby Saunders and her young son Paddy are both impressed with Justin's manner.

The Enterprise arrives at Chicota Landing with a cargo of gunpowder for the Army. Before they can unload it, the boat is taken over by a gang of Mexican bandits led by Juan Cortilla.

Louise Harrison and her boy friend, the only survivors of a boat tragedy, do some quick thinking. Realizing that a fortune in jewels went down with the ship, they appeal to their rescuer, Grey Holden, to help them retrieve Louise's ""dowry.""

French playboy Andre Devereaux has become an American lieutenant. Assigned to lead some troops into Indian Territory, he finds that the normally peaceful Indians have been provoked to violence.

To Captain Holden, his romance with Marie Tourette was just a pleasant interlude, until he discovers she is passing him off as her fiancé. While her family is in on the deception, they expect Grey to follow through and marry

For a price, simple-minded Hunk Farber is only happy to reveal the whereabouts of his boss, Monte, who accidentally killed a senator's son. The reward in his pocket, Hunk heads for Captain Holden's riverboat. There he is eager to impress a young lady aboard the Enterprise.

Tommy Jones, a young stowaway, is discovered aboard the Enterprise. Also on board is a pair of thieves, who plan to blow up the boat to collect insurance on some diamonds they are shipping to St. Louis.

A group of volunteer teachers who have gone to the island of Diablo Corozan off the coast of Tampico are imprisoned when Spain conquers the island. The corrupt Spanish officials allow Joan Marchland, one of the teachers, to return to the United States to raise a ransom for the rest.

In town to have an aching tooth removed, Carney stops at the saloon for a bolstering drink. This makes him late for the dentist, so Blake undertakes to separate Carney from his tooth.

While the Enterprise makes a stop for wood, a group of Cajuns board the vessel and hijack a part of the cargo. Two people are shot during the incident.