This quest is accepted from Barbatos. This is the first of two quests from Barbatos for upgrading the alchemy part of the tower. He asks you to go and find a book that an old alchemist friend of his once had. The only clue he gives is that the book is located in a cave somewhere in the Orobas Fjords.
You will find the book in the Dark Cave, which is Southeast of the passage to Broken Valley. The enemies in this hideout are around level 20. Near the entrance, one of the bandits randomly drops a key, which you will use to open a gate. Take the path to the left (East). At the end of this path, you will find four platforms and two locked chests at the end. One chest can be opened from a key that was dropped by the bandits. To open the other chest, and disable a barrier to the rest of the cave, you will need to stand on the platforms in the correct sequence.
When facing toward the chests, the platform closest to you is 1, while the platform closest to the chests is 4. The correct sequence is 3, 1, 4, 2. Each platform will sparkle when you step on each in succession.
In the same room as Ragon and his bandits, there are three golden dragon statues. When you use them, they will rotate. Rotate each statue until it will rotate no more. When all three have been rotated, the book will appear (with a small video showing it appearing). Take the book and return to Barbatos to complete the quest.
As with all tower quests, you will then be told to go see Sassan to apply the upgrade to that part of the tower.
The default reward is 4500 exp, 520 gold, and a Skill Book. The choice reward is either 1125 exp or 520 gold.
Attention: In the room where you find the 3 statues; when the book magically appears, pay attention to its back; you will find a Gold Bag on the ground, which, when looted, will give you: 3 Legendary items, OR 1 OR 2 Elder Items! (its possibly the best "chest" until this point of the game).