Another cistern.
Anubis's dim glow illuminated a difference, however: this one's gemstone grate had been shattered, at some point. Judging by the hanging ceiling, by a falling chunk of stone. Half of it was still intact and blocked the hole below: but the back third or so was broken, smashed free, so that someone could simply leap the dangerously long drop to the space beneath.
There was no telling if the drop was the same distance, here, or if the slope was the same as the last. But below the broken space, the tip of the huge chunk of fallen stone could be seen, perhaps six feet below, though its base was lost to the shadows.
@Anubis
Once Anubis reached the previous corridor, again, he would find two more cells to either side--and then yet another junction in the vast dark.
To the right, a tunnel that felt, somehow, more stuffy than the last. It was broad, but there was no flow of air or scent of water.
To the left, one that had a strange, stale scent, like ancient dust; the faintest echo of what sounded like dripping came from this direction, too.
And forward, myriad smells and sounds. Different odors of stone, of water, of something organic too, and dust. Air flowed, this way. Not enough to be called even a breeze, but it wasn't quite as still as in the last few corridors.
@Anubis
The brightness of these mushrooms was enough to give him a glow along the walls, instead of the faintest patches of light along the floor.
The path ahead was more corridor. A bit of rubble lay some distance ahead, after about three doorways on the left--more square cells. To the right, however, almost immediately, a much larger doorway opened: a crumbled, yawning gap, where an opening had been worn much larger by time. Just past it were piles of rubble, a fallen, shattered column of stone blocking some of the way... and light, somewhere beyond? It was faint, but it glimmered along the rubble within, and there was a distant dripping that echoed in a way that suggested a large, open space.
It was up to Anubis whether to enter that space to his right and investigate the light and rubble, or to continue forward down the tunnel ahead.
@Anubis
The rubble that stood between Anubis and the light would take some work to get around; winding between, or clambering over, either would take some effort. He'd find himself in a space as large as a few dozen of the cells: massive, open, yet with other walls to his left and farther on, in his way to the right. He could skirt around them, though a great deal of rubble was in his way there, too.
If he managed to reach the center of the room--rather a journey given the catastrophic amount of debris--he'd have a better sense of both its scale and layout. A huge space, walled-off sections around its edges double the size of the usual cells, their much larger entryways half worn and fallen away. Huge chunks of stone lay here and there, fallen away.
The entire back of the room was simply gone. Sharp ledges indicated a space where the foundation of this place had long ago crumbled, pitching its floors and walls in cascades of stone over millennia until they'd piled up somewhere far below. Here there was a dripping, and even a quieter flow of water, audible off of the ledge. And the entire area was lit by light: in places, here, the ceiling had collapsed, the rock into which the prison had been built not apparently very tall in this location. No water ran down into it, but it was audible down below, a light flow; and the scent of it, and of plants, was strong here.
Should Anubis risk a glance down off the ledge, he'd see an extremely far drop, with piles of the fallen room creating a labyrinth of water-flooded rubble, and plants having taken root wherever the light reached it.
Whatever was in the larger structures along the sides of this room would not be visible unless he investigated past their collapsed, darker entrances.
@Anubis