Handlung

It's 1941 and three Nazis escape from a Canadian prison. Two are killed but the third kills Paul Schiller and assumes his identity. This leads him to the Three Mesquiteers ranch where his uncle Dr. Steiner is developing a chemical that will extract rubber from a local plant. The Nazis are out to stop the project and they get the fake Schiller to sabotage the Doctor's formula.—Maurice VanAuken <mvanauken@a1access.net>

In 1941, three German airmen, led by Captain Carl Baum, escape from a Canadian prisoner of war camp and cross into Wyoming. Local ranchers grow nervous as radio reports of the Nazis' murderous flight southward are broadcast daily, and one in particular, Clem Parker, theorizes that other Germans in the country are aiding them. "Tucson" Smith, "Stony" Brooke and "Lullaby" Joslin, ranchers known as The Three Mesquiteers, try to calm Parker, especially when he casts aspersions on Dr. Heinrich Steiner, a German refugee scientist who, along with his daughter Laura, is developing a chemical that will aid in extracting rubber from culebra plants. One afternoon, after Lullaby admires an expensive gun in Jud Carson's general store, the Germans sneak into town, steal the gun and shoot Carson. Carson alerts the townsfolk before dying, and they assemble a posse to pursue the Nazis. One is killed during the chase, while another is picked up as a hitchhiker by the unsuspecting Steiners. The man forces the Steiners to take him to their home and then to shoot at the posse. The man is killed while trying to escape, and Parker, realizing that the Steiners were unwilling accomplices, agrees to participate in Heinrich's experiment. Meanwhile, Baum has hitched a ride from Paul Schiller, Heinrich's nephew. Paul, who has not seen Heinrich in many years, has come to Wyoming to help with the Steiners' work. Baum kills the young man, then presents himself as Paul in order to steal Heinrich's formula for Germany. Baum is welcomed by the Steiners and the ranchers, but shortly after his arrival, he is abducted by a group of secret Nazi sympathizers, led by German consul Von Breckner, who are unaware of his identity. Baum's Nazi tattoo proves his true loyalties, and the men agree to help in his plan to kidnap the doctor. The Mesquiteers foil their attempt, however, and become suspicious of Baum, especially when they find the gun used to kill Carson in his possession. Hoping to uncover the truth, the Mesquiteers and Steiner quietly send for Paul's mother, Elizabeth Schiller, but Laura, unaware of their intentions, tells Baum that she is coming for a surprise visit. Baum reports to his cohorts, who arrange to meet Elizabeth before she enters town. They warn her that they are holding Paul captive and threaten to kill him unless she pretends that Baum is her son. Elizabeth acquiesces, and the Mesquiteers are mystified when she warmly greets Baum. The day after her arrival, Heinrich prepares to conduct his experiment, but Baum contaminates the formula with acid to ruin the crops and turn the ranchers against the doctor. The first round of spraying is a disaster, with the crops dying almost instantaneously. While Heinrich struggles to determine what went wrong, the ranchers grow angrier. Curious about why Elizabeth has not come to watch the experiment, the Mesquiteers question her, and the frightened woman confides in them. They rush to the experiment site, as the ranchers, who have just heard on the radio that the Japanese have attacked Pearl Harbor, are about to lynch the doctor. The Mesquiteers forestall them with Elizabeth's story, and Baum and his cohorts, who have been inciting the ranchers, attempt to flee. The men are captured, however, and Baum confesses to killing Paul. Soon after, the American government offers to help the ranchers recover from the damage done by Baum, and everyone pitches in to help Heinrich use his formula to support the war effort.