For Knowledge

Last session, the party dove underground and found an underground chamber filled with udead and a stone sarcophagus at the center of the room. They managed to push through the horde, only to find a warning on the sarcophagus "Leave now. Lest you unleash a terrifying evil to this world"

After escaping and reevaluating their options, the party decides to fix the sarcophagus to stop the black smoke from emanating from it and hopefully clearing the undead.

It seem that they were right as they were able to meet with the treant they are looking for. While it has the knowledge they seek, it cannot follow them to Kontecol to perform their research. Instead, it pointed the party to another ruin where they found a stone throne that was able to provide them with the knowledge they seek.