Oubliettes are no place for the living. Especially if a ghul resides in it.
From Protector of the Grey House:
Natalia landed easily in a crouched position. She looked around, tried to see the creature, and couldn’t. The light from above didn’t penetrate deep into the dark dank cave. She could see enough to realize there were no bones on the floor, just dust. As she assessed the situation, she took deep slow breaths, to try not to gag. The smell was awful: as if rotten meat fermented in its own juices. She breathed through her mouth, and regretted it immediately. Sweat, fear, and pain were palpable on her tongue. Natalia turned to find the ghul. Nothing peered at her from the darkness, but she knew something watched her.
Then she felt it. A cold whiff of wind swept past her ear, brushed some hair back. Or rather, pulled it back. Her eyes flew open wide; she stood, and to spin around to face her attacker. There was nothing there. Natalia felt the tug in her hair again and turned again. Still nothing. This happened another time and Natalia felt panic rise. She clamped a mental door on her panic, and stopped her thoughts. If she were thinking too much, then her warrior side would not come forward. Calmed, Natalia turned in the opposite direction from the tug and saw something in the shadows.