The Stormcast Eternals of the Hallowed Knights must brave Nurgles's Realm of Decay if they are to find their lost leader, Lord-Castellant Lorrus Grymn.

As the war for the Realm of Life continues, Lord-Castellant Lorrus Grymn leads the battered remnants of the Steel Souls warrior chamber against the sargasso-citadels of the Verdant Bay. The Hallowed Knights claim victory, but at a terrible cost - Grymn is lost to the Realm of Chaos. Now Gardus, newly reforged and fresh from the destruction of the Scabrous Sprawl, must lead his warriors into the foetid heart of Nurgle's realm in search of the Lord-Castellant, where they must once more brave the horrors of the Realm of Decay...