Prophet (Dawnguard)

Background
''Serana told me that her father was trying to gain power over the sun by fulfilling a prophecy found in the Elder Scrolls. If we could read the prophecy, we might be able to stop him. Serana had one of the scrolls, but we'd need a Moth Priest in order to read it.''

Discussion
After talking to Isran, he leads the Dragonborn to talk to Serana, who arrived at the fort to tell the Dawnguard of her father's plans. Upon talking to Serana and Isran, he allows Serana to stay if she does not touch anyone. Serana says they need a Moth Priest to read the Elder Scroll she brought, and Isran says an Imperial scholar has recently arrived in Skyrim.

Serana recommends the Dragonborn find the moth priest, and says she will go with the Dragonborn, only if it is just her and the player. Any follower must be let go to allow Serana to follow, although there is a glitch that allows Cicero to come as a second follower. If the Dragonborn does not take Serana as a follower, she stays at Fort Dawnguard.

Ask a Carriage Driver
Ask any carriage driver outside a city if he has seen a Moth Priest. He will mention that he's not sure, but can be persuaded or bribed for answers. The driver will reveal that the Moth Priest asked him to take him to Dragon Bridge.

Ask an Innkeeper
Ask any innkeeper in any city if they have seen a Moth Priest. They will say that the Moth Priest had recently stayed in the inn, on his way to Dragon Bridge.

Visit the College of Winterhold
Head to the College of Winterhold, and speak to Urag gro-Shub in the Arcanaeum. He will reveal that a Moth Priest came by to study in the library, but left for Dragon Bridge.

Dragon Bridge
Upon reaching Dragon Bridge, ask the guards or Clinton Lylvieve about the Moth Priest's whereabouts. They will mention that he left south across the bridge a short while ago.

Travel south across the bridge and eventually find an ambushed carriage. Search the vampire corpse for a Vampire's Note  indicating that the Moth Priest was taken to Forebears' Holdout.

Forebears' Holdout
Upon entering the cave, head left and kill or sneak by the death hounds and vampires before crossing over to the main building and up the stairs to the upper platform. The Moth Priest, Dexion Evicus, is being held here in a magical barrier.

Once all the vampires are dead, search Malkus' body to find a Weystone Focus. Place the Weystone on the altar above the barrier to deactivate it. Dexion Evicus will awaken, but will still be partially enthralled. After defeating him, he will come to his senses and thank the Dragonborn. After talking to Dexion, he will agree to help read the Elder Scroll and will head to Fort Dawnguard.

Travel back to Fort Dawnguard and report to Isran. Next speak with Dexion, who will begin to read the Elder Scroll. He first sees a vision of Auriel's bow, then a voice whispers to him about a dread lord of the night who will rise up in a time when dragons return. He then reveals that two other scrolls are needed to learn the secret of the bow's power and complete the prophecy. One scroll contains the ancient secrets of the dragons, the other speaks of the potency of the ancient blood. Once the reading is complete, the quest ends and Chasing Echoes and Seeking Disclosure begins.

Elder Scroll reading
Dexion: "I see a vision before me, an image of a great bow. I know this weapon! It is Auriel's Bow! Now a voice whispers, saying "Among the night's children, a dread lord will rise". In an age of strife, when dragons return to the realm of men, darkness will mingle with light and the night and day will be as one.

The voice fades and the words begin to shimmer and distort. But wait, there is more here. The secret of the bow's power is written elsewhere. I think there is more to the prophecy, recorded in other scrolls. Yes, I see them now... One contains the ancient secrets of the dragons, and the other speaks of the potency of ancient blood.

My vision darkens, and I see no more. To know the complete prophecy, we must have the other two scrolls."
 * Serana must be present for reading

Bugs
Prophet (Dawnguard) Пророк (Стража рассвета) Prophet (Dämmerwacht)