It was surely still early, and whether the sun was up was a matter of debate down there. The well-hidden, lonely and clearly insane creature slain, the party gathered up the actual valuables it kept, and struck out into what seemed to be the only clear way forward, the other options being rat tunnels that only a halfling could negotiate.
They set the dervish out in front once the hallway turned to a tunnel that narrowed to single-file, she being able to detect traps as well as put up a good fight in a pinch. The rest of the party carefully followed behind, just in case she missed anything. She announced she could hear water ahead, likely some underground stream. Farther along, the chittering of rats. After 50 feet of this careful progress, the tunnel widened into a large natural cavern, the water still out beyond the edge of torchlight.
Suddenly huge numbers of rats scurried across booted feet, temporarily flooding the floor with disease-carrying rodents, but none attacked. A woman’s voice from within the cavern called out for help suddenly, the voice vaguely elven in tone, and a couple of the men in the party strode forward to help! But the dark of the cavern caused slow progress, and only one of the dwarves managed to step out of the light for a bit to see a humanoid figure scramble over a 10-foot pile of rubble that looked like an old cave-in.
Some headed south to discover the quickly moving stream that cut through this area. Most others though moved toward the rubble wall, asking for lights to be doused or covered, trying to find out where the woman went. Those with infravision clambered over carefully to see what was on the other side. Just as their eyes adjusted and started to make out the details of a chamber with rat-holes up high, only accessible by rock shelves and ledges, a dozen feet off the ground. The footprints of the woman who ran through were barely visible as their heat faded, and various warm-bodied shapes were apparent near the rat-holes. One of the larger bodies made a throwing motion and a cold object could be seen sailing toward the four adventures on the top of the wall…
The cloud of dust that exploded from the thrown bag caused the four to cover their mouths and duck for cover, but Radek was slow to react and inhaled a lungful of it, causing him to cough and sneeze and choke… and die.
The first shots were in the dark, all those fighting able to see the heat of life. The one who threw the sack fell into a magical slumber, and his apparent mate cried out and charged int. As the battle began to intensify, many of the party surged over the wall, bringing their lights so all could see.
It was dozens of giant rats, crawling over each other and the entire base of the wall to claw and bite at the party. The “mate” who ran to attack was apparently humanoid, but his build and features were strongly ratlike, enough to call him “rat-man”. Poisoned arrows were shot from the high positions as the giant rats stormed the front lines. Spell casters managed to keep the attackers at bay for the most part, either putting them to sleep or commanding them to attack each other.
After a solid minute of chaotic fighting, the battle ended with the party victorious… Most likely.