Flame Hashira Kyojuro Rengoku receives new orders: Travel to the Mugen Train, where over forty people have gone missing, and conduct an investigation. Leaving the Demon Slayer Corps Headquarters, he sets off on this new mission.

Trapped in Enmu's spell, Tanjiro, Zenitsu, Inosuke and Kyojuro fall closer and deeper into an eternal slumber. Faced with death, Tanjiro is forced to confront his demons to save them.