Unpopular at school because of his high I.Q., neglected by his weak and alcoholic father, Marvin is easy prey for the campus vamp, Betty, who pretends an interest in Marv only so that he will write her term paper. When the two are discovered cheating by their professor, the longed-for scholarship recommendation is withdrawn. Meanwhile the jealousy of Betty's boyfriend has been aroused and when Marv learns that he can only hold the girl's affections by offering her riches, he plans a million dollar robbery. Even the professional gangsters with whom he works are amazed at the brilliance of the young genius.
A sleazeball (Ronald Long) who supplies women to his public-relations clients explains the rules of the game to his latest acquisition (Jeanne Rainer).
Both Scotland Yard and an amateur American sleuth are tracking a master criminal known as The Frog. This moniker refers to the bulging-eyed mask worn by the evildoer, and is reflected by the frog icons painfully tatooed onto the forearms of his henchmen. The trail leads to the country manor of an enigmatic, steely-eyed nabob, whose repressed son has eyes for the artistes at the Lolita cabaret, and whose lovely daughter captures the fancy of both the American playboy and the villain himself. Murder, kidnapping and seduction ensue.
Mystery writer Cornelia Van Gorder has rented a country house called "The Oaks", which not long ago was the scene of some murders committed by a strange and violent criminal known as "The Bat". Meanwhile, the house's owner, bank president John Fleming, has recently embezzled one million dollars in securities and has hidden the proceeds in the house, but is killed before he can retrieve it.
A young alien falls for a pretty teenage Earth girl and they team up to try to stop the plans of his invading cohorts, who intend to use Earth as a food-breeding ground for giant lobsters from their planet.
In Prohibition-era Chicago, musicians Joe and Jerry witness a mob hit, and flee the state in an all-female band disguised as Josephine and Daphne, but further complications set in.
US Army Officer Dan Adams, blinded during the war, is framed for a diamond smuggling rap. Upon regaining his sight, Adams goes after the real thieves in an effort to clear his name. In order to trap the wily criminals, Adams pretends that he's still bereft of his vision.