Publisher's blurb: Ios, the Overseer of Duerradin, a highly advanced duergar psionic research outpost, invites you to discuss the recent activity of the Heir of Orcus and her worshipers, the Cult of the Heir. Explore Duerradin for clues leading to nefarious plots carried out by the Cult of the Heir, discover alien technologies found nowhere else in the Forgotten Realms, and learn the dark history surrounding the rise of Duerradin before the Heir of Orcus strikes!