After the death of the Dark Lord, The Doom Slayer was once again sealed by the Ancient Gods. But unknown to all of them, the Slayer's soul has been transported to a world where humanity is in a verge of extinction.

Right after the events of Doom (2016). After Samuel Hayden's infamous betrayal, the Doom Slayer is expelled through a new dimensional portal. However, the Slayer finds himself trapped in a hell which he did not even know existence. In this completely foreign place but where the demons seem to know him, he will meet Charlie, the young princess of this hell, who curiously, also seems to know the Slayer, at least by reputation. The Slayer will then discover that his legend extends far beyond what he could have imagined.