The Stormvaults are the hidden treasure-vaults of Sigmar, secret repositories scattered across the Mortal Realms in which the God-King has concealed artefacts and powers too dangerous to be left in the open. Sealed by celestial magic and guarded by the stormcast-eternals, each vault holds relics, weapons and imprisoned entities of tremendous might.
Within these arcane strongholds Sigmar locked away the spoils of the Age of Myth, the deadliest sorceries and the most perilous godbeasts and daemons his hosts could bind. Their locations are kept secret even from many of his own servants, for knowledge of a Stormvault is itself a weapon that enemies would kill to obtain.
With the coming of the Necroquake and the wider war for the realms, the seals of the Stormvaults have weakened, and many now become battlegrounds. Servants of Chaos and Death alike scheme to breach them and claim the treasures within, while Sigmar's warriors fight desperately to keep the vaults' terrible bounty sealed away in darkness.