Kyren Elnisis brings the party inside her office. "You did well in the mines and I think you can help with something else as well. We have been having some problems here on the lakes with the Whistler (Capybara)s in the area. Their numbers have been increasing over the last few cycles inside the Cavern. I believe something is scaring them from their homes in the ruins. Can you find what is out there and get rid of it?
Discussion may happen here with a few question and a price negotiated is possible as well.
The ruins of the Lake Stratum are very dangerous. Large bats can fly down and snatch people with barely a sound. The ruins themselves are unstable and even 9000 years later can fall without just a small change of weight. Since the Whistler uses it as a nest, this has also drawn other predators; snakes and reptiles hunt them and their nests. Travelers in the ruins must be extra cautious.
The party may run into large snakes or other predators that they can choose to fight or hide from. They must also be careful of the large bats as they fly above the ruins. To find clues they will have to track things into some of the buildings, many may fall as they try to enter and will have to try and get out or get buried. This is also dangerous as it attracts other predators to the scene.
The party will find clues like magical runes on some of the buildings and holes that look like something dug its way out. The runes may be difficult to identify, but they are necromantic in nature.
The party will find the tracks of the things from the holes lead to a large structure that looks in pretty good condition. As they approach the structure they will see a large number of skeletons wandering around. The party may attempt to fight them or sneak past them into the structure.
DM Note: If the party chose to fight outside, the people may hear the fight and send the undead inside outside to reinforce. They will also be prepared to fight the party in defensive places. This description assumes they sneak in.
Inside the structure, there appears to be a group of people controlling the undead. There are also a few undead in here, although the bulk are outside. The room is brightly lit, which will make it difficult for the the party to get very close. If watched without getting caught, the party will see them doing a magical ritual on an undead. If they let the ritual finish they will see the skeleton disappear. It will reappear a few moments later. The group watches with anticipation until it does. When it reappears, it seems to glow with a dull light and the group appears happy by the event.
DM Note: If a member of the group gets close enough to overhear conversation, most of it appears to be related to "the final stage" but they do not go into specifics. It is clearly exciting for them though.
The Group will continue this ritual with each undead inside. There are 12 total inside the structure. Depending on when the party decides to attack, will depend on how many of the glowing skeletons they may face. The party may also choose to go back to the city and gather the guard to strike at the group. There are 15 people of varying skills in the group.
The leader of the group may attempt to summon a demon to help them fight, if successful, it will join the fight.
The Final Stage appears to be the day they launch their enhanced skeletons at the city. The runes were to root out the dead that have been buried since the Great Quake and animate the bones. The enhanced skeletons can flash a great light that will summon smaller demons to fight. This would turn a small army into a much larger one in moments while blinding those nearby.
The cultist group were the survivors of a larger group that was executed for blasphemy. They self exiled into the ruins and have been out here for a few years planning their revenge. This plan was still in the beginning stages as they were unaware the Whistlers were driven away by their runes.