Tanjiro and his party heal their wounds from the battle thanks to the actions of Shinobu, a member of the 'pillar', and achieve a state of constant concentration.
And with new orders, the group boards the "Mugen Train" and, together with the flame pillar Rengoku, exorcise the demons hiding on the train! However, this all happens in a dream created by the demons, and Tanjiro and his group are caught in the dream!! Is there really a way out of this predicament?!