Seymour Gutz has become the Mutagen Man again, and hes randomly mutating New Yorkers all over the city! In facthes even mutated Michelangelo! (Did you know you could further mutate a mutant? The Teenage Mutant Ninja Turtles sure didnt!) The Turtles need to get Seymour back to TCRI to formulate a curebut 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!