The state is funding a scientific experiment to create biological weapons in the strictest secrecy. When deadly amphibians with altered genetic code accidentally break free, the government does everything it can to cover it up. By spraying poison into the ocean, scientists think the monsters are dead, but that's a mistake. A battle with a raging nature is imminent.

After betting his horse, Patrick Brennan is forced to set off on foot on a long journey. Along the way he is picked up by a stagecoach carrying newlyweds, Willard and Doretta Mims. At the next station, the stagecoach and its passengers fall into the hands of criminals. The gang is led by a man named Frank Escher. When Escher learns that Doretta is the daughter of a wealthy copper mine owner, he decides to ransom her. Tensions rise over the next 24 hours as Escher awaits a response to his demands, and a romantic attachment grows between Brennan and Doretta.