After discovering an abandoned underground Foot Genetics Lab, and being attacked by once-human Digging Creatures, the Turtles assist those very creatures in trying to repair a Force Field.

After befriending the once-human creatures in an abandoned underground Foot Genetics Lab, the Turtles join them on a journey deeper into the earth, where they come upon the ruins of a once-great subterranean city.

When Michelangelo and Leonardo are out getting a little night air, they cross paths with a caped crusader who ends up saving their lives. The Turtles soon learn that he's really a cop who is out to get the one man who ruined his career.