Strahd's Apparatus Manual

A diary of Strahd von Zarovich about the use of the Apparatus; useless without the Rod of Houtras. Stolen by adventurers and then later taken from them by Lyssa von Zarovich, whom conspired with the High Master Illithid to use it to overthrow the Illithid God-Brain and fabricate an army of illithid vampires.

As of the contemporary time in universe of the Thoughts of Darkness module, the manual was hidden behind the tapestry that lies near the Might Master Illithid's bed., though it might be taken by the player characters and delivered to the Brotherhood of Contemplative Power for a reward, as determined by the Dungeon Master.