After Roy Rogers and the men of the Valley Pipeline Company risk their lives to put out an oil fire from a leaking pipeline, they find that a mysterious object piercing the pipe had caused the oil to escape. Splinters Fedders, who works for a nearby government experimental station, rides up and identifies the object as a rocket that his team is in charge of retrieving, and promises that Roy's company will be reimbursed for the damage. In the distance, Gregory Camwell, the owner of a neighboring oil well, watches the fire and comments to his companions that the burned-up rocket is not useful to them. He then introduces himself at the experimental station, and makes a sales pitch to sell and deliver the oil they need. The person in charge, Dr. J. D. Manning, refers Camwell to his bespectacled and serious daughter Frankie, to work out the delivery and payment details. Manning then orders Frankie to go to Roy's company and reimburse him for the damaged pipeline. When she arrives, Roy accidentally hoses her with chemicals, but offers to replace her clothes. Upon returning from town many hours later with a new hairstyle and clothes, she is more relaxed, and admits that her father's work keeps her isolated. Manning shows up, angry and rude, and orders Frankie to return to work, but before she leaves, she mentions Camwell's company, which interests Roy, as Valley Pipeline delivers other companies' oil to the nearest slip port. Hoping to get a new customer, Roy visits Camwell Oil, but is beaten for trespassing and sent away. Camwell makes plans to deliver oil to the station the next day, but because his own well is not producing, sends his men to steal it from Valley Pipeline. That evening, Roy rides out to check a pipe that has been reported leaking, and is shot and left bleeding by Camwell's men. His horse, Trigger, runs to the experimental station for help, and Frankie brings Roy to the camp's infirmary until he recovers. Several days later, Camwell delivers more oil to the station and learns from the over-friendly Splinters the time of the next rocket launch. On launch day, Frankie tracks the trajectory of the rocket for Splinters' retrieval team. However, Camwell's men carry the rocket away before Splinters' group arrives and remove instruments from the rocket that predict long-term weather conditions. Camwell explains that their usefulness in military strategic planning makes them valuable to others, who will pay him for their delivery. The men replace the equipment with a time bomb and pack up the weather devices. Meanwhile, after exhaustive searching, Splinters returns to the station without the rocket and Manning blames Frankie's tracking. She sneaks off to Roy's office, where Roy is meeting with an insurance inspector, who reports that the company's second oil leak was caused by someone who was stealing directly from the pipeline. Frankie and Roy ride out to the site where her trajectory pointed and find the rocket where Camwell's men left it. Splinters' team takes the rocket back to the station, but Splinters insists that the area was searched earlier. Manning apologizes to Roy for his behavior, and admits he feels stressed by his tight work schedule. Seeing his dog Bullet fuss over the rocket in the wagon, Roy realizes the rocket is ticking. He drives the wagon far from the station and barely escapes the blast of the bomb. Putting everything together later, Roy and Splinters guess that Camwell's company is a front for traitorous activities. They plan for Splinters to round up other men and follow Roy to Camwell's office. However, one of Camwell's men knocks out Splinters before he can alert anyone. Upon arriving at Camwell's place, Roy is overcome in a fight, loaded onto the wagon with the weather devices, and driven away. Splinters recovers, and with his men, takes a wagon to find Roy and the villains. As they catch up, a shootout erupts between the two racing wagons. Most of Camwell's men are killed or apprehended, but Camwell attempts a desperate escape back to his office. Roy jumps on Trigger, who has been following behind, and pursues Camwell. During a fistfight with Roy, Camwell climbs his oil rig and falls to his death. Later at the station, Manning again thanks Roy for his help, and everyone returns to work.
