Après avoir enquêté sur le crash de plusieurs météorites, le docteur Forrester est persuadé que le phénomène n'est pas naturel. Sa théorie se confirme lorsque des extraterrestres envahissent la Terre et plongent la population dans le chaos. Pour empêcher l'invasion, le gouvernement prépare une attaque nucléaire…

In the 17th of the 24 films in Monogram's "Range Buster" series, Texas ranch owner Conroy returns from Washington with an order for horses to be shipped to the Philippines. The Range Busters, Dusty, Davy and Alibi, are selected to take the horses there but, before leaving, they capture three spies who are trying to steal the horses and also learn that the ranch cook, Cookie, is a Japanese spy, but he manages to escape. In the Philippines, they go to a café for dinner and see Cookie and Miller, a German spy. Eavesdropping, they learn that Ken Richards, a neighboring Texas rancher, is the Axis contact back in the states. They capture Cookie and break up the spy ring in the Phillipines, and then return to Texas intent on settling matters with Richards. They do so and are honored by the U.S. Government just as the radio blares forth the December 7, 1941 announcement of the Pearl Harbor bombing. They head for the nearest enlistment station.