Black Book: Filament and Filigree (Quest)

Walkthrough
The book Filament and Filigree can be found at the end of Kolbjorn Barrow, after Ahzidal has been defeated. Activating the book will transport the Dragonborn to Apocrypha where a Black Book is located.

The level consists of a long bridge with several floating lights, populated by several Seekers and Lurkers. Stepping into the darkness causes health to rapidly drain, so using Candlelight or a torch can prevent this.

Defeat the creatures to reach the black book at the end of the gauntlet. Read the book to complete the quest.

Reward
After activating the book one of three abilities is granted as a reward:
 * Secret of Strength: Power attacks cost no stamina for 30 seconds.
 * Secret of Arcana: Spells cost no magicka for 30 seconds.
 * Secret of Protection: You take half damage for 30 seconds.

Only one ability can be chosen at a time, but the chosen ability may be changed by reading Filament and Filigree. This will transport the Dragonborn back to the end of the level in Apocrypha and allows selecting a new ability.

Bugs

 * The sizzling burn damage effect and audio can persist once you have left Apocrypha and returned to Solstheim.
 * Solution: You read the book again and go to Apocrypha. Then before you go back to Solstheim, make sure you're not in the shadows.
 * Solution: Save your game, quit then re-load.
 * Upon returning to Solstheim, the sky will appear somewhat like it does in Apocrypha.
 * Solution: Clear Skies shout will remove the effect.

Journal

 * Learn the Black Book's hidden knowledge.