3 Ninjas Knuckle Up: Rocky, Colt and TumTum must battle an evil wealthy toxic waste dumper in order to save a local Indian tribe and their friend Joe. The 3 Ninjas must help find Joe's father and find a secret disk that contains evidence that could stop the toxic landfill that is destroying the Indian community. However the town is owned by the rich man and he controls the police and even the mayor. They must fight a motorcycle gang and renegade cowboys in this non-stop ninja adventure.