Episode Title:The Lonely Mutation of Baxter Stockman.Episode Description:Donnie finally discovers a Retro-Mutagen that can restore Kirby to his human form as he, the other Turtles and April set out to find him. Meanwhile, Stockman gets mutated by Shredder into the housefly mutant "Stockman-Fly" for his 74 consecutive failures to create a perfect mutant army. When he finds out about the Retro-Mutagen, he kidnaps April and demands that the Turtles hand it over to him in exchange for her, prompting the Turtles and Casey to go and rescue her, whilst facing off against Razhar.