Episode: 5 Move Forward

After waking up from his dream by cutting his own neck, Tanjiro battles Enmu, who is the source of all the turmoil on the train. Enmu appears to be getting pleasure from inflicting pain on the passengers, which only infuriates Tanjiro even more. Tanjiro succeeds in severing Enmu's head, only to discover that Enmu's body is fused with the Mugen Train itself. Tanjiro is backed into a corner, but a freshly-awakened Inosuke comes to assist him and... (Source: Crunchyroll)