A young man is raised in the mountains by his prizefighter father. Although he possesses great strength and athletic skill, he is completely out of his league when it comes to women.
Inventor Peter Marchmont has discovered a purple light that renders the user invisible. On his release from prison, Marchmont, disguised as Victor Cromport, uses the light to revenge himself against his former wife, Jewel, and her partner, James Dawson, who framed him for theft.
Automobile maker John Kent is an old-fashioned sort who refuses to advertise his car line. His daughter Ginger, however, is determined to get him some publicity and goes speeding around town in one of his cars, hoping to get arrested.
Jack Standish feels responsible for the failure of the partnership with his father and goes to the South Seas where he falls prey to alcohol, is seduced by Lullaby Lou, a vamp, and tricked by a brutal plantation owner, Gordon Van Brock.
The gang is trying just about anything to pass the time during their summer vacation. As usual, Mickey and Jack are trying to win the affections of Mary.