A Watery Prison

The abject darkness that Lars was subjected to was achieved very simply.

In the first place, they were already underground; all lighting had been man-made, or rather, magic-made. Pearls of light, non-incendiary torches or magical runes; all these cast meagre but passable light for the gloomy passageways and rooms in this subterranean fortress.

The second thing that happened was the total and complete submersion of the compound under frigid waters, channeled from the neighbouring Gorun River!

One second it was dry and well-lit; the next, pitch-dark with surging currents of smashing waves flooding the rooms!

'Crazy! He'll kill not just us but everyone in the entire hideout with this - no, he must have suitable preparations to avoid sacrificing his top subordinates down here!'