You receive this quest from Darkstare in the Boardroom of Gods.
They say that you'll need Coventina's help in order to awaken Habren.
They say Coventina is being held prisoner in the Fortress of Balor and you'll need the Chalice of Restoration to free her.
The giant Albion lives in the Hills of Llyn Cau posses that chalice.
The chalice will also be used to restore the confused mind of the god Nodens.
You will receive the Persuade the Giant quest
Go to the Cliffs of Albion, which are located in the Northern part of the map.
Enter Albion's Realm, which is located in the Northwest corner of the Cliffs of Llyn Cau.
Get Gamogs' Key, which is located in the Northeast part of Albions Realm.
Use Gamogs Key to unlock the bottom Southeast corner door in the Realm of Gamog.
Get the Giant's keys which are located in the Northeast part of the Realm of Gamog.
The Giants keys are used to open the Northeast corner door in Albion's Realm.
Albion tells you the Chalice of Restoration is lost beneath the Lake of Llyn Cau.
He says he also lost his favorite club in the lake and asks you to find both the chalice and the club.
He says if you find and bring his favorite club and the chalice, you can keep the chalice.
You will receive the Explore the Lake quest.
Complete that quest, then you'll have the Chalice of restoration.
Return to Darkstare in the Boardroom of Gods.
The Persuade the Giant quest will be solved.
You will receive Darkstare's Fang and Darkstare's Claw.