Skyrim Dawnguard Walkthrough Dawnguard Side Part 14: Inner Sanctum

After filling the Initiate's Ewer in all five Wayshrines in Darkfall Passage and the Forgotten Vale, your next objective in the quest "Touching the Sky" is to gain entry to the Inner Sanctum. From the last wayshrine, go north and northeast towards the big building. Climb the stairs and pass through the gate, cross the bridge,  climb some more steps, and arrive at the temple courtyard with a big statue of Auriel in the center. Climb the stairs from either side, and pour water into the basin. Wait a few seconds, and the Inner Sanctum door opens.

The halls inside the temple are full of frozen Falmers. In the first hall, interact with the Shrine of Auriel to receive the Blessing of Auriel. Go through the door to the north, then enter the inner hall north by northwest.  In one of the next rooms, find a hole in the wall to the west. Travel through the tunnel, and enter Auriel's Chapel.

You have to locate Arch-Curate Vyrthur. Drop down to the lower level, then go east through a narrow corridor. Arrive at the throne room. Confront Arch-Curate Vyrthur who is sitting at the throne. After the dialog is over, the Forzen Chaurus and Frozne Falmers in the chamber come to life and attack you.

After you defeat the enemies, Vyrthur pulls down the ceiling causing debris to fall on you. If that's not enough, he also summons a Frozen Frost Atronach. Eventually the ceiling collapses. There is a big explosion and you fall on the ground. Vyrthur escapes to the balcony. Serana urges you to get up and give chase. Head east t the balcony. Wait for Serana to catch up. She talks to Vyrthur, demanding the bow. Serana realizes that Vyrthur is a vampire himself. He wants to take revenge on the god Auriel for not protecting him. After the dialog between Vrthur and Serana ends, attack Vyrthur and kill him.

Speak to Knight-Paladin Gelebor, who shows up on the balcony, and tell him what happened. He is shocked to find out that Vyrthur was a vampire. He thanks you for restoring the chantry, and agrees to give you Auriel's Bow.

Retrieve Auriel's Bow to complete the quest, Touching the Sky