Romance and Doom Sequel: Kaitlyn Grimm, friend of the Teenage Mutant Ninja Turtles, has been keeping her vigilante activities a secret from her Uncle, Ben Grimm of the Fantastic Four. He begins to notice subtle changes in his niece's behavior, but before Ben can learn the truth, he and the rest of the Fantastic Four are captured by a villainous duo who plan to take over the city.