Should Have Been (S02E03)

Tanjiro, Nezuko, Zenitsu, and Inosuke team up with Rengoku aboard the Mugen Train, aware of the potential demon threat lurking within. Despite their vigilance, they gradually succumb to sleep. In his dream, Tanjiro encounters his long-lost family, a heartwarming reunion that soon takes a sinister turn. It becomes clear that this idyllic scene is nothing more than a cunning trap orchestrated by Enmu, the Lower One.