After the secure vault of the Arcanum is robbed, Steward Tethren hires the PCs to recover the lost notebooks of Kaz; Tethren explains that the books contain dangerous knowledge that needs to be suppressed. Livia and Bors make contact with Guildmaster Hex, who with some posturing and prodding steers them towards the fled master thief Mask of Rivest.
After pursuing him in windwalk, they teleport ahead of his position and seek to meet him as he flees to Viminok. However, they find that a village in Ardun Vale infested and surrounded by horrors from the Dark Tapestry. After cutting their way through the monsters, they track the thief to his cache and recover an additional book full of unspeakable lore. This book is destroyed.
Investigation also shows that the work of Kaz consists of research and experiments into advanced alchemy, including more powerful bombs, oils, and other (largely violent) advances. Debating whether or not to reveal the information or give it back to the Arcanum, Ivory commits as much information as possible to memory and returns the notebooks.