They were half way down the ladder, on the fifth platform.

“Why not?” Gotrek replied. “You wanted to find out what happened to the Kislevites.”
“Under the circumstances, I’m pretty sure I can guess.”
“Guessing isn’t good enough, manling. There may be some humans alive down there, and they granted us fire and shelter.”
“Fire and shelter and a bucket of vodka for Snorri,” added Snorri helpfully.
“That settles it then,” Felix said sourly. “I’ll gladly sell my life for a bucket of vodka.”
Felix knew he was just grumbling for the sake of form. Even if the two Slayers had not been there, he liked to think he would continue anyway to find out the fate of Ulrika and her family. Flanked by Gotrek and Snorri there was no turning back. He consoled himself with the thought that if there were skaven down there, a lot of them were going to die.
Unless they have some of those terrible sharpshooters, Felix thought. Or even some with crossbows. Easiest thing in the world to pick us off from a distance. Or maybe not. Not in this light. Not with all these wooden crossbars around. And Snorri and Gotrek were short; they would not make good targets. Of course, that left one obvious target for any sniping. He tried to push the thought from his mind as he put his weight on the rungs of the ladder once more.

A glow surrounded Grey Seer Thanquol. For a moment Ulrika stood frozen, wondering what new horror the skaven sorcerer was about to unleash. The aura of power that surrounded the creature was almost overwhelming. The skaven raised two objects it had taken from its pouch and began chanting something in its own high-pitched tongue. All skaven eyes in the room were upon it. The rat-ogre growled as it sensed the gathering of power. Ulrika decided that it did not matter what the skaven was up to. This was her best chance to do something. Whatever wickedness Thanquol was about to commit, she would put a stop to it.
She sprang forward and sent her booted foot crashing into Grey Seer Thanquol’s groin. The skaven gave a squeal of pain and bent over double, dropping his sorcerous adjuncts. A strange smell of musk suddenly filled the air. The rat-ogre roared and reached for her. She dived forward, below its outstretched claws. They missed her by inches as she passed between its columnar legs and headed for the door.
The skaven shrieked in confusion. Ulrika threw the bar on the door and dashed into the next chamber. The rat-ogre bellowed its rage behind her.