Seymour Gutz has become the Mutagen Man again, and he’s randomly mutating New Yorkers all over the city! In fact…he’s even mutated Michelangelo! (Did you know you could further mutate a mutant? The Teenage Mutant Ninja Turtles sure didn’t!) The Turtles need to get Seymour back to TCRI to formulate a cure—but first they need to rescue him from the Shredder, who has captured him with the desire for the Mutagen Man to create an army of mutants!