Detective Michael Shayne (Lloyd Nolan) is hired by horseracing commissioner Hiram Brighton to keep an eye on his compulsive gambler daughter, Phyllis Brighton (Marjorie Weaver), while he is away in New York. Shayne also is offered but turns down a job to collect money from gambling racketeer Harry Grange (George Meeker), who welched on a bet. Soon, however, Shayne discovers that Phyllis has ties to Grange and that he is helping to enable her gambling habit. To teach Phyllis a lesson about keeping seedy friends, Shayne decides to stage Grange’s death. However, the plan backfires when Grange turns up murdered, and Shayne is suspected of the crime. With the help of Phyllis and her mystery novel-reading aunt (Elizabeth Patterson), Shayne sets out to clear his name, uncovering a deadly web of intrigue, blackmail and greed. ‘Michael Shayne: Private Detective’ is the first of 12 films in the ‘Michael Shayne’ series. The first seven (1940 to 1942) star Lloyd Nolan, while the last five installments (1946) star Hugh Beaumont, who went on to portray patriarch Ward Cleaver on ‘Leave It to Beaver.’