Four teenage mutant turtle brothers live a hidden life in the sewers. Trained by their master, they have become highly skilled ninjas—the Teenage Mutant Ninja Turtles. Eager to be accepted by the human world, the four brothers, with the help of their human friend April O'Neil, begin tracking down a mysterious crime syndicate. But when a powerful army of mutant creatures descends upon the city, the Turtles—mutants themselves—realize they are facing their biggest threat yet…