The plot revolves around a rivalry between sand-hog "Hard Rock" Harrigan (O'Brien) and his foreman Black Jack Riley. At the center of their conflict is their mutual affection for heroine "Andy" Anderson (Irene Hervey). But when the chips are down and Riley is trapped in a tunnel cave-in, it is Harrigan who comes to the rescue.

A female private eye joins forces with a police detective to investigate the suspicious murder of a millionaire.

A waiter who sings gets in a fight with rude customers and overpowers them. A boxing promoter sees this and transforms him into "Kid Nightingale," marketing him as a boxer who sings.

A successful songwriter and a struggling singer become involved professionally and romantically on the road to stardom.

A police lieutenant is determined to bust the gang of crooks selling defective automobile tires.

When a prisoner on Death Row is "accidentally" killed just before his execution, a reporter smells something fishy...

A crime reporter writes book to expose names and methods of the criminal leaders. He is held on a charge after refusing to explain how he got his information, but is released and helps to expose the syndicate.

Unusually elaborate for a PRC film, Minstrel Man is a lively musical drama built around the talents of veteran vaudevillian Benny Fields. The star is cast as Dixie Boy Johnson, who rises from the ranks of minstrel shows to become a top Broadway attraction. On the opening night of his greatest stage triumph, Dixie Boy's wife dies in childbirth. Profoundly shaken, he walks out of the show, leaving the baby to be raised by his showbiz pals Mae and Lasses White (Gladys George, Roscoe Karns). The kid grows up to be an attractive young woman named Caroline (Judy Clark), who follows in her dad's footsteps by billing herself as-that's right-Dixie Girl Johnson. This leads to a tearful reunion between Caroline and the father she'd long assumed to be dead. If Minstrel Man seems at times to be a dress rehearsal for Columbia's The Jolson Story (1946), it shouldn't surprising: the PRC film was directed by Joseph H. Lewis, who went on to helm Jolson Story's musical highlights.

Brass Bancroft and his sidekick Gabby Watters are recruited onto the secret service and go undercover to crack a ruthless gang that smuggles illegal aliens.

On leave in Italy, Lt. Tommy Knowlton falls in love with Jean Standish, who's not only married, but is the daughter of his submarine's commander. Friction between the two officers becomes intolerable once at sea and after Commander Toler is forced to abandon Tommy's best friend topside while the sub dives to escape enemy planes, Tommy is no longer able to contain his anger.

Suspecting that a safari guide is a wanted killer, undercover policeman Geoffrey Bishop (Richard Fraser) joins a safari led by the suspect for a scientist that hopes to find and prove that a fabled white gorilla is a missing link.

In this drama, a trucker's business is nearly destroyed after he is wrongfully accused of killing a policeman with whom he recently quarreled.