In the world of the Pokémon Mystery Dungeon games, Arceus the Creator has been imprisoned in a nightmare by Darkrai, who wishes to seize control of the world. Pokémon are being turned against each other, and even killing each other. The only hope for the world lies in three mysterious heroes of prophecy. Can these heroes free Arceus and restore order to their world?

Twenty-one Pokemon have all been invited to the same place- a mansion in the middle of the ocean. But what will happen when the Pokemon are slowly being killed off one by one? Welcome to Unova Mansion. Rated M for Drama, Death, and Violence.