In the First Era, there was a lord in Skyrim named Harkon. Afraid of death, he made a deal with the Daedric Prince Molag Bal: he sacrificed thousands of his subjects to Molag Bal, who then turned Harkon and his family into vampires.
That way, Harkon no longer had to worry about dying. He could live forever.
Since these vampires had been turned by the Daedric Prince Molag Bal himself, they were stronger than ordinary vampires. They didn't even have to worry about being burned by the sun, though their powers were slightly diminished in daylight. This clan of vampires was known as the Volkihar...
And now, judging by the information gathered by Isran, the leader of the Dawnguard, and Vigilant Tolan, the ones who had been active throughout Skyrim lately were none other than the Volkihar vampires and their minions!
They had also learned something about the Elder Scrolls. The vampires were searching for some kind of artifact, likely one of the Scrolls! That was exactly what they were discussing now, and the arrival of two newcomers, one big and one small, in the Dawnguard castle hall hadn't interrupted them at all.
"Tolan!"
"Why have you come here? If I remember right, the Vigilants and I haven't had anything to do with each other for a long time..."
"No!"
"Isran, I think you know why I'm here. The Vigilants are being attacked everywhere, and those vampires are an even greater threat than we imagined!"
"I see. So you've come to ask the Dawnguard for shelter. Am I right?"
"But I distinctly remember the Vigilant Keeper Cassie constantly telling me back then that Fort Dawnguard was nothing but an ancient ruin on the verge of collapse, and that it wasn't worth spending people or money on repairs."
"And now, you've