Ragathan the Mad stumbled into a frozen alleyway near the Mooncaller's encampment, his mask, a crude imitation of the ritual mask worn by the blessed Mooncaller himself, worn askew so that he could gulp from his bottle of fungus brew. The human barbarian finished his business, then noticed something odd in the corner of his eye. He lifted his mask off, thinking it was some trick of the beer, but no. There it was, a green glowing rent in the wall, not quite the familiar glow of the Bad Moon. Deeper, more sickly. Beside it, a crude sign, complete with a poor illustration of what might have been a rat, read:
WELCOME TO GNAWMARKET! ALL YOU FAVOURITE GOODS FIND HERE!!
Perhaps it was the beer, perhaps the madness for which he was named, but Ragathan found himself stumbling towards the rent, his empty bottle forgotten on the frozen cobbles behind him.
The lurch in his stomach as he passed through almost made him lose the fungus brew he'd just ingested, so he leant unsteadily on the wall as he recovered. It was rough black stone, comparatively warm after the cold of the frozen city. He continued on a short way. There was firelight at the end of the rough hewn corridor, a torch in a sconce illuminating a hunched man. No, not a man. A skaven.
There were few Skaven in the Mooncaller's retinue, and those that were were conniving and untrustworthy killers. Devoted followers, to be sure, but dangerous. Ragathan took a hesitant step back.
"No-no, no, my friend! Do not run-flee!" Said the creature, holding its paws up in a placating gesture, "this good place! Lots to buy. My master sources from all across the realms!"
"Master?" Slurred Ragathan uncertainly, only now noticing the tattered coat the rat man wore, like something out of a circus.
"Oh yes-yes! My most bounteous master Gribblesnak Snikklekrak is the finest purveyor of goods in the realms, and famous for his marvellous-amazing trained barter rats!"
"Barter… rats?" Ragathan was starting to feel more curious than afraid at this point, and started to follow the peculiar creature.
"Oh yes-yes, come look-see for yourself. No fights though, or rats eat you. And don't try to leave through any other exits or you die-die and rats eat you."
Some of Ragathan's forgotten anxiety began to return, but he followed regardless. It seemed as if the corridor would go on forever until, disorientingly, it suddenly opened out onto a well-lit, bustling marketplace in the bowl of an enormous cavern. There were all types of people here: the skull-wearing corsairs of the Blackwing side-by-side with the duardin of the Dross-Forged and beyond. Surprisingly, there seemed to be very few Skaven in attendance, the stalls seemingly unmanned.
He was confused until they came closer, and he had to rub his eyes fearing that this may all be an elaborate hallucination brought on by the fungus brew. But no, it was as the hunched skaven who was leading him had said, there really were barter rats. Squeaking, furry bodies ran back and forth with coins and esoteric goods clutched in their jaws or ferried along on the scabby backs of a dozen or more working in concert. Some even seemed to be haggling, accepting or denying lower payments and twisting their wormy tails to form numbers.
Unable to tolerate the assault on his addled senses a moment longer, Ragathan collapsed into a drunken heap on the cavern floor, startling a brace of rats as his considerable weight pounded the stone. "I'm off the brew this time, swear it on the Moon." He muttered to himself, and promptly threw up.