The battle for the Imperium's future rages as Roboute Guilliman confronts his traitor brother Mortarion and the Death Guard in the heart of Ultramar. Guilliman, the returned primarch, seeks to reclaim his ancestral home and use it as a springboard to restore the Imperium of Mankind. However, his campaign to drive the Death Guard from Parmenio is complicated by the intervention of a greater power, forcing Guilliman to question his understanding of the galaxy and his own role within it. This conflict unfolds within the grimdark universe of Warhammer 40,000, where primarchs and their ideologies clash in a desperate struggle for survival.

As the second installment in the Dark Imperium trilogy, Plague War continues the epic narrative of Roboute Guilliman's struggle to restore the Imperium of Mankind. The novel is expected to deliver the signature grimdark atmosphere and large-scale conflict characteristic of the Warhammer 40,000 universe. Readers anticipate a deep dive into the ongoing war against the Death Guard and the existential threats facing the Imperium, with the introduction of a 'greater power' promising to expand the lore and challenge established perceptions. The clash of primarchs and ideologies is a central draw, offering a continuation of the grand cosmic drama.