City of the Ilmatu

Three days north of Ilvo we found what we thought was a house; a tiny single-roomed dwelling built of heavy stone blocks that were greened with Arctic lichens. There was an arch where we thought a door had once been, and inside there was barely enough room for the four of us. Rainer, who had organised this expedition, kept looking around for something, while the rest of us puzzled over it.
"It's too small," said Matias. "Even for one person it's just too small. Where would he sleep, where's space for a fire? It's not a house."
"The stone seems rather too much for a folly though." Guldtronen's voice was always deeper than his appearance suggested.
"Actually," I said slowly, "where did the stone come from? There are no quarries north of Ilvo, the land's too frozen. And this stone, it's basalt isn't it? That's volcanic."
Rainer was staring up at the ceiling, which was vaulted and dark. He vanished outside and returned with a torch, which he shone up at the ceiling.
"It's a bell-tower," he said, waving the yellow circle of light over a rusted spur of branching metal that hung down from the ceiling. "It's not a free-standing structure, it's the top of one."
"That's ridiculous," said Matias, but Guldtronen and I had looked down straight-away, and we both saw the iron ring in the floor. I pointed, but Guldtronen knelt and freed it from the dirt. We all backed away, and he heaved on it. For a few seconds he strained, his breath grunting out of him, but nothing happened. Then there was a crack that echoed in the tiny space and part of the floor jerked upwards. Once he'd freed that much pulling the trapdoor open further was far easier, and shortly we beheld a dark square opening into something below the room we were in.
"Ropes," said Matias, accepting that Rainer might be right. "If it's a bell-tower then ropes would have hung down through here. Stairs would have been off to one side."
"Or outside," said Guldtronen. "When we arrived I thought the stonework at the base was strange."
He was right, although we had to dig a little, and in frozen tundra that's no easy task, there were stairs that had been carved into the outside of the tower. Which were useless for us unless we wanted to try and dig the entire tower out with just the four of us and shovels.
There were ropes in the sleds, and in the end we tied one end to a sled because there were no safe anchor points inside the tower. Then, Rainer excitedly leading the way and acting like a child in a sweet-shop, we climbed down the rope into the darkness.
At the bottom, in an icy chamber where our breath condensed in front of us in white clouds, we found a corpse. It was that of a young man with a thick beard, and showed no sign of decay. His eyes had been taken from his head, and his nose had been cut off, we thought; two slits of nostrils in the centre of his face all that was left. In hind-sight, we should have been a lot more suspicious about the lack of decay, but at the time we were more shocked by how he'd been defiled.