The virtual world of ID: Invaded is full of tumbling, floating houses, colliding masses of land, and disappearing structures. Sakaido, a detective, finds himself in this world, and is quickly tasked with unraveling the murder of Kaeru, a young girl who was fatally stabbed. Soon it becomes apparent that the unconventional physical rules of the new world aren’t limited to buildings or roads since Sakaido’s body also presents various states of disconnection.
When Lord El-Melloi II, the later Waver Velvet, gets asked to claim his inheritance over Adra Castle, he travels there with his apprentice Gray to do so. But they are not the only ones called that way. The will of the previous owner states that the assembled contestants—including Luviagelita Edelfelt—must compete in a game of wits to win the castle.