Teenage Mutant Ninja Turtles animated

"Keeping the city safe is hard work for the Teenage Mutant Ninja Turtles, and it's even tougher with a vigilante roaming the shadows looking to settle a score with the city's mutants. But could this new street fighter be an ally? And when Donnie creates his greatest achievement--retromutagen--it'll take the whole team to make sure it doesn't fall into the wrong mutant's hands!"--Back cover.