Upon his return to the Old World, the ambitious Grey Seer Thanquol is coerced into leading an army against the dwarfs of Karak Angkul. Renowned for its engineer clans, this city will not fall easily, but the true object of Thanquol's fascination is their secret artefact of incredible power which he believes will assure his ascension to the Council of Thirteen. His efforts are thrown into disarray when the infamous skaven Ikit Claw usurps control of the army for his own nefarious schemes, and so Thanquol must act quickly before the warlock can unleash his ultimate weapon: the Doomsphere.