Atlus U.S.A. today revealed the details on the Tome of Lost Souls, the pre-order bonus art book from Knights in the Nightmare for the Nintendo DS. If you pre-order now, you'll also get a soundtrack CD, besides the 7"x10" full color art book packed with each launch copy. The gameplay from Knights in the Nightmare is a mix of roleplay and strategy, as you're in control of a Wisp and you have to activate the souls of deceased knights to aid you in destroying foes on the map. Find and recruit the ghosts of seven different classes of knights from your kingdom, and learn of their pasts, hopes, dreams, and untimely deaths. Sacrifice their souls to one another to balance their skills and create your ultimate party. Knights in the Nightmare is scheduled for release on June 2, 2009 with an MSRP of $34.99. Check the new batch of screenshots from our gallery and the press release for details on the art book.