The Hero of Kvatch must talk to him to gain access to the Shrine of Mehrunes Dagon, located within the Lake Arrius Caverns. He asks the Hero to give him all their items before letting them inside. Alternatively, the Hero can kill him and loot the door key from his corpse. The later course of action will turn all the Mythic Dawn hostile against the Hero, making infiltrating the cult impossible.
"Dawn is breaking."
- Greet the new day. "Welcome, brother. The hour is late, but the Master still has need for willing hands. You may pass into the Shrine. Harrow will take you to the Master for your initiation into the service of Lord Dagon. Do not tarry. The time of Preparation is almost over. The time of Cleansing is near."