Tears of the Kingdom takes place a number of years after Breath of the Wild, at the end of the Zelda timeline in the kingdom of Hyrule. Link and Zelda set out to explore a cavern beneath Hyrule Castle, from which gloom, a poisonous substance, has been seeping out and causing people to fall ill. There, they find a mural depicting the founding of Hyrule and a subsequent conflict known as the Imprisoning War—an ancient battle against a being only referred to as the "Demon King"—and decide to ventur