After a fight with Shredder causes Donatello to be struck by a laser beam, his personality changes to become a costumed superhero known as the Dark Turtle. His mission: Seek out & destroy Shredder. Meanwhile, a dinosaur-like alien race called Triceratons, invades Earth.

Kerma the space turtle returns once again for the Turtles help in programming his city's new defence robots but Groundchuck and Dirtbag have also returned to the city to cause trouble.