You receive this quest from Gamog in the Realm of Gamog.
Go to the Cliffs of Llyn Cau and enter Albions Realm.
Gamogs' Key located in the Northeast part of Albions Realm.
Use Gamogs Key to unlock the bottom Southeast corner door in the Realm of Gamog.
Talk to Gamog.
He asks you to find Addanc Dripina. She's one of the most powerful water spirits.
She will give you a giant protection potion to save the White Feather Giants.
You'll find Dripina in the River of the Addancs.
You'll also need the ability to see Addancs to be able to talk to her and get the potion.
You'll receive the quest Persuade Dripina.
You will need to get the Addanc Sight Ability to be able to see and talk to Dripina.
To get the Addanc Sight Ability, refer to the Build a Bridge quest.
When you have the Addanc Sight Ability, you can find Dripina in the Northern part of the River of Addancs.
Talk to her and she will ask you to go back and ask Gamog to send someone powerful enough to blow up the dam that holds the Addancs prisoner.
You will receive the Blow up the Dam quest.
When that quest is complete, you will have the Giants Protection Potion.
Go back and talk to Gamog in the Realm of Gamog.
The Persuade Dripina quest will be solved.
You will receive 30,000 gold.