Walkthroughs for the Vasthelm Quest series from Dibella's Watch, a large user created plugin for Oblivion. After exiting Hoegborg Castle in A House of Horrors, the player discovers that the Hellrise are attacking.
The Winter War
There are a lot of enemies that will attack your side in this quest, so it is quite likely that some non-essential people will be killed.
"The General tells me that the city of Vasthelm itself is under attack and that enemy forces have appeared right in the centre of town! There are no reserves at all since all troops are fighting the Hellrise out here by the line; only the town guards are now struggling alone. I am therefore to take Gaiseric with me and clear the entire town from enemy presence. We are the reserves - him and me."
"The Hellrise have broken into Castle Vasthelm. The Valkyrie guards are putting up stiff resistance, with the help of my crusader friend Cerize. She's now going to protect the princess, while Gaiseric and me are tasked with exploring the Castle Dungeon and shutting the gate down there through which the Hellrise are entering the castle."
"We have succeeded in closing the gate between Castle Hoegborg and Vasthelm. The Mad Magician's Grave down here was obviously a secret passage the enemy used to enter the castle. We should now go to Cerize in the Princess' Quarters and affirm that the Princess is safe."
Return to the Entrance Hall of the castle where the spirit of the Mad Magician speaks to you.
"We met the Mad Magician and he damned us for defeating his army. Without army, he's lost his power, and is now condemned to walk Castle Hoegborg forever as a ghost. His fate is quite sad, since he really came looking for company and love, but he brought this upon himself by going about things in violent and hateful ways. Now we're going to go see that the Princess and Cerize are safe."
Enter the Princess' Quarters and Cerize speaks to you, which completes the quest. Go to the Throne Hall and speak to the King. He wants you to get Gasteric and Cerize to make peace with each other, as you will have noticed they don't get on that well, as they are father and daughter.
This final quest is easy to do as all you need to do is speak to people who are quite probably standing next to you. After speaking to King Thor to start the quest, speak to Cerize.
"Cerize tells me she's going to work as the head of the Valkyries in Vasthelm and that she's not going to follow her father's wishes anymore. I think that's fair enough."
Now speak to Gasteric.
"Gasteric has started his job as the new First Minister in Vasthelm. I should go tell Cerize what he said about her."
Speak to Cerize again, which completes the quest. She also gives you the Vasthelm Home Key, so you can enter the Vasthelm home and have a place to stay there.