Dan O'Hara, known as "Big Dan," returns from the war, and finding that his wife has left him, turns his home into a boys' camp and begins to train boxers.
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.
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.
Billy Buell (William Farnum), a stranger involving himself with a long-standing mountain feud. The Benchleys and the Camps have been feuding ever since Lew Camp (J.
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.
Robert Wells is an American born in China who, unbeknownst to him, has an Oriental half-brother. Wells' uncle sends him to help Ray Williams build bridges in China.