The Teenage Mutant Ninja Turtles are back! Leonardo, Donatello, Michelangelo and Raphael must save New York City and the planet from several new threats! Their old enemy Shredder and mutants he creates with the help of Dr. Baxter Stockman, a T.C.R.I scientist, seek to destroy the brothers. The alien invader Krang and his forces from Dimension X want to take over the world. Only with the help of their human and mutant friends, including Master Splinter, April O'Neill, Casey Jones and Vern Fenwick, can they push back the bullies and villains to make their city and world a safer place.