After entering the Infinity castle to attack and hopefully defeat Muzan Kibutsuji The Demon king the Hashira would soon realize that it wouldn't go as they hope they're plan was backfiring badly losing many of they're fellow Demon slayers in battle with the Uppermoons they decided that they had to retreat or try to but they found themselves lost in the Infinity castle not knowing where they were or where they came from when they ran down another hall and saw You