It was a room so bare it held only a single bed, with a thin blanket carelessly spread over it.
The walls were made of obsidian, and the only window was a foot square, barred by several iron rods as thick as a baby's arm.
"You'll have to conjure a chair yourself, Voldemort. I don't have one."
Grindelwald sat on the edge of the bed and pulled the thin sheet around himself. He seemed rather sensitive to the cold.
"All right."
Voldemort tapped his cane, and a chair materialized out of thin air behind him.
"What do you want from me?"
Before Voldemort could speak, Grindelwald continued, "Don't give me those lies you used to deceive Dumbledore. You know I'm not like him."
Voldemort frowned and looked at him in confusion.
"You said you wanted to learn from my failure, didn't you?" Grindelwald asked.
Voldemort nodded. That was indeed what he had said at the foot of the mountain.
"But that's wrong in itself, Voldemort. Failure is failure. The only thing you can taste in it is bitterness." Grindelwald shook his head with a sigh.
"But there must be lessons to learn, right?" Voldemort asked.
"Yes, there are for me. But not for you."
As he spoke, Grindelwald extended his right hand from beneath the thin blanket. It was frighteningly pale.
"Whoosh."
A restorative ripple appeared in his grasp.
It flowed freely across his hand, like a nimble little golden snake.
Antonio appeared from who knew where. He glanced at the Phoenix on Voldemort's shoulder, then at the restorative ripple in Grindelwald's hand.
Then he hurried over to Grindelwald's feet and tugged at the blanket, trying to climb onto him.
"Thump."
The blanket suddenly bulged. Judging by the angle and position, Grindelwald had probably kicked him.
Antonio was sent tumbling