"The blood shall be a sign for you on the houses where you live; and when I see the blood I will pass over you, and no plague will befall you to destroy you when I strike the land..."
Killed Silveroak drops 1-2 level 39 rare (blue) chest.
From the bridge leading south out of Thorshafn, follow the river going southwest. Keep going until you see an area on the right that looks like a burned down forest. In this area, there will be a section of raised ground that you can only reach by going through a hollow log.
On this high ground, walk out onto the dead tree that hangs over the edge. From the tree, hop down onto a tree stump.
Carefully leapfrog between the nearby stumps, go up the branch on the last stump; you are now in Silveroak's lair.
Approximate Location: 18000,22000