A Troublesome Tome is a quest in Dragon's Dogma
You get it from Steffen near the fountain square in Gran Soren
He wants you to recover Salomet's Grimoire.
Contents
Objectives
Learn More of the Grimoire
Steffen asks you to locate Salomet's grimoire, a tome empowered wit arcane magicks. It seems the book yet remains somewhere in Gransys
Explore the Thieves' Den
Investigate the Thieves
Details
The grimoire is stored somewhere in the bandits' hideout. Search the area and claim the tome.
A band of thieves has apparently claimed the tome. Head for their territory in the south of Gransys.
Walkthrough
Go to the red marker in the south and help Rowland who is under attack
Then go to Ruins of Aernst Castle southwest of Witchwood
Climb to the top of the tower and then climb on the wall to get to the top edge, where a chest with the grimoire will be located.[1]
Note: If you go to Dragon's Dogma: Ruins of Heavenspeak Fort you can talk to the female bandit leader Ophis who tells you about the rival gang in Aernst Castle headed by Maul. But you don't need to talk to neither Ophis or Maul to complete this quest.