Adventure Time: Heart of Darkness is a second sequel to Adventure Time ZX and Adventure Time: Re-Awakened. Unlike the previous ones where they are comedy, this one approached in a more darker tone. The story takes place right after Re-Awakened, with Finn awakes 4000 years later from the Capsule, where he sees a futuristic Mobius, now renamed Neo-Earth and its now populated by humans. Now Finn has to form a new team and fighting new villains.