Regarded as the best of Columbia's "Lone Wolf" B-picture series, The Lone Wolf Spy Hunt stars Warren William as Michael Lanyard, a onetime criminal known as the Lone Wolf. He is determined to remain reformed for the sake of his daughter (Virginia Weidler), but a gang of foreign spies abducts Lanyard and force him to steal the blueprints for a secret anti-aircraft gun. Ever the ladies' man, Lanyard has two lovelies to contend with here: dizzy heiress Ida Lupino and seductive spy Rita Hayworth (just prior to her superstardom). Lone Wolf Spy Hunt is a remake of 1929's The Lone Wolf's Daughter, and like the earlier film is based on the character created by Louis Joseph Vance. Incidentally, the character of the daughter would never be seen or heard from after this 1939 film, though Warren William would make seven more appearances as the Lone Wolf.