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.

A Florida-bound train is filled with romance and intrigue when one of the passengers disappears while carrying $11-million in unset jewels.

Trouble-prone Billy Peck and his gang descend on a traveling circus that has just hit town, and before long their antics are causing the circus owner all kinds of problems.

Champion boxer Jimmy Dolan has cultivated a wholesome image for himself, but he's a boozer and womanizer behind the scenes. Intoxicated at a party, he punches a reporter who threatens to expose his hypocrisy, and accidentally kills him. Dolan panics and skips town, winding up on a farm that serves as a home for disabled children run by kindhearted Peggy. As the cynical Dolan falls for Peggy, he begins to change his ways.