Together we are stronger

The elfin arcane archer, Shaft, was staying with Ilsa Starmane at her Greyhawk estate. She seemed nice enough, though the Grugach elf guards were gruff and they warned not to go into the courtyard lest he be attacked by the guardian beast. So far he had stayed only a few weeks, with the occasional dinner with Ilsa and her cousin Aurora. Shaft tended to make these occasions infrequent, as a house guest he would have to produce a gift of wine or a succulent treat discovered within the grime of the sprawling human city. Additionally, Shaft was trying to spend as little as possible to marshal his remaining coins. So far he had lived off the gold from his adventures 4 years ago, and at the current rate he could loaf for another decade before having to find 'real work'.
Ilsa summoned him to the parlor, and in the presence of her Grugach captain, she seems dishevelled, gaunt, with hair barely combed and lacking any make up. Quite a difference from the elfin lady of refinement he had seen but a few nights before.
She quizzed Shaft for a bit, until she dismissed her guard and told him how she had been kidnapped and held for months by seeming shape-shifters. Dopplegangers, in a secret prison near the river.
When Shaft told the lady that he had seen her recently, she asked Shaft to seek out her rescuers and get their help in dealing with the fake Ilsa and anything else in the compound. She told Shaft of her rescuers and he realized they were members of his old adventuring group from Diamond Lake. Aardgal, Krech and Felnar had escorted her and were returning to the secret prison, though they were wanted by the authorities, and may be in hiding or taking a secretive route through the city.
Shaft headed out at once, and within a few hours found the building which Ilsa had mentioned and quickly drawn a map. Shaft checked inside the old warehouse and found the front doors both unlocked and dark inside. Shaft climbed up a nearby warehouse, and settled in to watch anyone coming of going to the building in question.
Darkness turned to dawn, then into day as the City awoke and people went about their daily business. Shaft was starting to get antsy, when around 10ish he saw a group of three heading from the street to the warehouse entrance. Two merchants, one lightly armored and a heavily armorer man with a Furyundian tabbard in red and gold. After a minute Shaft recognized them as the three adventurers who had escorted Ilsa Starmane back to her compound. Krech, Felnar, and Aardgal. Shaft quicky scrambled over the side of the warehouse he was on. He hung and dropped and identified himself, sence he hadn't seen his old comrades in months. He quickly filled them in on Ilsa and her apparent 'replacement', likely a doppleganger. Aardgal suggested they reconnect with Morgrim, Bornir and Azrael before doing anything.
The four adventurers entered the dark warehouse. Krech used a new magic item, called a watch lamp, attached to his helm to provide illumination. Inside the warehouse they had just left yesterday, a large pit was open in front of a door, and large pools of milky white slime lay on the ground.
Felnar found the Mostly avoiding the pools of strange material was sticky, and the 4 avoided touching or stepping in the goo. They retraced their steps back to the prison cells. The doppleganger jailers were gone. Their cell door ajar.
The 4 then moved beyong a set of double doors deeper into the complex. There they found a room with large sharpened pilons and planks spanning what remained of the wooden floor. 5' Below lay fetid water and a myriad of rusty spears and swords placed in the muck below to skewer anyone falling into the water.