A rancher is murdered after discovering that 40 head of his cattle have been rustled. A neighboring family is accused of the crime and flees across the border, then tries to find the real killers to clear their name.

Homer Crow, fired from his laboratory job at the Dunn-Wright Rubber Company, is sure that his formula for an indestructible rubber, called Durex, will be a success. Others are also, and Honer endures many obstacles, prat-falls and staged accidents while striving to protect his inventions.

After Slug Raton takes Brady's horse, hat, and gun, the Sheriff arrests Grady thinking he is the outlaw. Slug's men chase them to Ricard's ranch which they burn. After Grady saves the Ricard's from their burning house, Betty Lou saves Grady from hanging at the hands of the masked vigilantes. Grady recognizes the voice of Raton among the vigilantes and now knows who to go after.