A Doctor's Diary is told through the eyes of Dr. Dan Norris (John Trent), resident physician in a private hospital. In his search for a cure for spinal meningitis, Norris recklessly runs roughshod over the feelings of his colleagues. The doctor's older, wiser supervisor, Dr. Clem Driscoll (George Bancroft), tries to curb Norris' impatience, pointing out that nothing takes place overnight. Angrily, Norris accuses Driscoll of malpractice and is forced to resign from the clinic -- just when a meningitis epidemic breaks out.

Set in an Old Dark House, a man is murdered in his study. With his dying breath, he tells his brother of two clues to finding hidden Eastern Indian jewels that were part of a precious idol. He wants his brother to locate the treasure, so that it can be given to his son. But before the treasure can be found, a third clue must be discovered.

Country girl Jane Budden goes to the big city, determined to find and marry a wealthy man. Instead, she meets and marries Herman Maxim, a struggling inventor.

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.

Wishing to dispose of his wife, psychiatrist Dr. Elliott makes his patient Nina think that she suffers from a compulsion to kill. He drugs Nina, murders his wife and leaves evidence that points to Nina. The latter, pre-conditioned by Elliott, also thinks she is guilty.

Bumbling policeman P.C. Josser is dismissed from the force after a disastrous attempt to distinguish himself at a nightclub. Mistaking his own comrades for criminals, he inadvertently "bowls them over like nine-pins," leading to his immediate firing. After losing his job, Josser sets himself up as a private detective. He is hired by a young lady who owns a racehorse and needs protection for her "favourite" horse before a big race. To protect the animal, Josser goes undercover as a stableman. Despite his efforts, the horse is drugged, leading to further comedic mishaps as he attempts to solve the case and redeem his reputation.

A woman is married to the son of a doctor, the proprietor of a private sanatorium, where she is under unwilling treatment. Both the son and the doctor indicate they want the marriage dissolved. Arriving at the scene is a mysterious personage identified as the doctor's cousin who formerly was a stage magician in Europe. He is accompanied by a threatening dwarf.