In a world populated entirely by Pokémon, the player awakens transformed into one of them, remembering nothing except that they were once a human. Almost immediately they are set upon by a group of mysterious Beheeyem, only to be rescued by a kindly Nuzleaf who offers them shelter in the peaceful community of Serene Village. There they meet a well-meaning but overeager partner, an outsider like themselves who dreams of joining the famous Expedition Society, a band of Pokémon explorers who investigate mysteries across the land. Together the two are drawn into a growing crisis: Pokémon everywhere, even mighty legendary ones, are being turned to stone by an unknown malevolent force. Inducted into the Expedition Society, the player and partner venture into ever-shifting dungeons, battling foes and unraveling clues in search of the truth behind the petrifications, the player's lost human past, and the darkness threatening their world.