Blood of Baalshandor

Blood of Baalshandor: Arkham Horror Novella – Rules of Play says:

Discover the power of true magic in Blood of Baalshandor! This Arkham Horror novella by Richard Lee Byers invites readers to return to Arkham alongside Dexter Drake as he searches for arcane tomes that can shed some light on the secrets he first glimpsed in a torn page from the Necronomion during the Great War. Lured to an auction of occult items, “Drake the Great” and his assistant Molly Maxwell find themselves targeted by the depraved servants of an otherworldly force of disease and corruption. It will take more than a little misdirection to get the magician out of this scrape.