The lizardmen offer any assistance they can to Earmy, so he can free them from their shackles.
The party talks to them for a while, learning that they have been enslaved here for quite some time now. They know about the horrible experiments, Yarash has been doing on their kin and others, and they are sure that they would have suffered that very same fate themselves, eventually.
Even though, they were used for hard labor here, they are not dumb and have observed a lot of details over time, hoping to eventually make use of their knowledge in an attempt to get free.
One very important thing they have seen is, that the wizard has a teleporting pad in his study, which he used to get out. They also know of a secret door in his study, which leads to the outside of the pyramid. There are other captives in here, and they wish to free them, too. They know how to do it, and now that the wizard's might has been broken and he is no threat anymore, they are sure, that they will be fine.
Searching Yarash's study reveals the teleporter and the secret door, as well as two interesting books. His spellbook (details will be added to the INFO thread soon) and a journal, which details his gruesome plans. Apparantly he was trying to build an army of mutated fishmen and other aquatics, in order to dominate the Moonsea eventually. His plans were laid out for decades, he was already working on them for about three. The contamination was meant to destroy the natural balance of the region, leaving his adapted creatures in the superior position. And with hundreds or thousands of them, he would be the supreme master of the region. There are also a lot of valuables there, which total about thirty thousand gold pieces.
Stopping the pumps is not difficult with the help of the lizardmen, who know how to operate them. They can be safely destroyed now. The black stuff was created by some sort of alchemical process by Yarash himself, the lizardmen do not know much about this, and there have been no notes. Hopefully, the wizard has taken the knowledge with him to his grave.
In order to thank the adventurers for their freedom, the lizardmen pledge the assistance of their tribe to them. They live in the swamps many days to the north-east from Phlan. While they will probably be of little use for the tasks inside Phlan, they can offer a safe camp in the wilderness, if needed, and their chieftain is very old and wise and has seen a lot of things. He has been here even before the dragon army raided the region. Maybe he will be able to offer some valuable information.
The lizardmen teach the adventurers a secret word, which to them means 'Special Friend'. They shall speak it loudly while they approach their settlement, and no harm shall come to them.