origin ver. section3(6)

But soon, tales began to reach Spire Stonebluffs – tales of slave caravans seen at the mages’ monastery. Slavery was not permitted under Greymane rule, so Hakon sent his soldiers into the mountains. Yet they never found a thing.
Years later, a scout gave word that a strange chamber had been carved high in the cliffside. Hakon, wise as he was, suspected treachery, so he, his son, and a hundred of his finest soldiers traveled there, seeing the very same altar and terrible door that remain there to this day. The mages were gone, their vile work complete. When Hakon’s soldiers neared the door, the loyal wolves turned against one another, slaughtering themselves in a fit of madness.
A vile presence spoke to Hakon then. Its voice shook the mountainside, offering the Greymanes untold power and respect should Hakon embrace the darkness. When he turned to look upon his son, Hakon finally saw the piles of mutilated corpses between them – his soldiers, the finest wolves of their clan. That, he realized, was the price of refusal. Without another word, Hakon entered the tunnel and the doors closed behind him, never to open again.
Thunder leaned back in his throne. “Until today.”