JUNIOR G-MEN (1940)--a colorized 12-chapter serial in one video.

The serial is one of the three serials starring "The Dead End Kids and Little Tough Guys" who were under contract to Universal at the time. The plot of Junior G-Men is a pre-World War II G-Man story about fifth columnists in the United States, with the FBI joining forces with youth to save the country.
A group of saboteurs called the "Order of the Flaming Torch" who are trying to undermine the "social order" of the United States kidnaps several prominent scientists, including Colonel Robert Barton, the father of Billy Barton, the leader of a group of young local street toughs.
When FBI Agent Jim Bradford investigates the mysterious disappearances, Billy is reluctant to help the authorities. Billy's gang team up with the FBI and the youthful "Junior G-Men", led by Harry Trent in order to stop the saboteurs.
The criminal gang led by a man called Brand, calls themselves "The Order of the Flaming Torch". They are intent on destroying important military programs. The enemy agents become aware that they boys are on their trail and set a trap. When Billy and Harry are captured, they find a way to signal to their friends, and are rescued.
"The Order of the Flaming Torch" is after the inventor of a new aerial torpedo. Billy and Harry go to the local airfield and hide on one of the inventor's aircraft. When the pilot is knocked out by one of Brand's men, the boys struggle to regain control of the aircraft. Finally successful, Harry, a licensed pilot, takes over and flies to safety.
Learning that the enemy agents are holed up in an old warehouse where scientists including Colonel Barton is held, Billy and Harry try to free Barton, who has a secret formula for an explosive. Managing to send a message out from a radio room, the boys are saved when FBI agents overrun the warehouse. Billy is finally reunited with his father, and becomes a full-fledged member of the Junior G-Men.