Below is a walkthrough for the Secrets Hidden in Danger subquest in Valkyrie Elysium.
Obtained: Interact with the white orb in the library at Valhalla after completing Chapter 7.
Objective: Find the Skill Tome
For this quest all you need to do is follow the linear path and defeat the enemies along the way. When the last enemy falls, a chest will spawn and the quest will clear.
Rewards:
- Punishment Blast III
- Mortal Suppression III