April O'Neil, ace reporter for Channel 6, investigates recent break-ins, allegedly by Ninjas, which have resulted in the thefts of numerous technologies. A chance encounter with a gang of thieves soon leads her to a bigger story when she is saved from the criminals by four Ninja trained, mutated Turtles.

Just when the Turtles believe themselves rid of Shredder, tin-grin is able to persuade Krang to return him to Earth.

A robot warrior arrives from 400 years in the future in 20th-Century New York.

Professor Lloyd Cycloyd, a crazy scientist who escaped from an institution, accidentally discovers the Turtles' lair. He sees Donatello testing out one of his new inventions, a time stopper.