Each of the vaults will have a small subquest you have to complete in order to finish the quest The Forgotten and the Damned.
another one on Body in the unfinished Crypt,.
One Silver bar can be found right next to it,.
Two of the hatches will need a Silver Lever Shaft that can be made by putting silver into the ancient forge (X:314, Y:475).
They will explode and reveal entrances to 3 vaults.
Sing the hymn to the 3 statues near the demon camp.
One of the Blackring members will drop it as well.
Archives on the northeast of the island.
The books real name is "The Taming of the Holy Fire" after you decipher it.
You will need a party member with the Scholar Tag to decipher it. (not sure where to find the map but it's not needed to complete this quest) Walkthrough
You can acquire this quest from ? at Bloodmoon IslandĪfter coming across a map, we learned of several hidden vaults scattered across Bloodmoon Island, along with a forge and some sort of archive.
The Forgotten and the Damned is a side-quest in Divinity: Original Sin 2.