The 88-page Forbidden Power book tells of the battle for the Midnight Tomb, as the spectral armies of Nagash lay siege to the free city of Lethis, seeking to break into the Grand Stormvault hidden beneath its streets. In addition, you will find new rules for recreating the armies that fought for Lethis, for fighting battles in the grim region of Shyish known as Stygxx, and for playing a campaign to conquer multiple Stormvaults hidden across the Mortal Realms to capture the powerful relics within. Theres something for every faction in the book, so no matter which grand alliance you fight for or the deity you serve, your army can fight for the right to loot the forbidden Stormvaults too!