After clearing the first room, they find Lady of Decay serving Zain-kin, planted into the marshy ground. After killing them before they could awake, the group poisoned the ground and prevented its future use.
They also find evidence that Elwind is being held further in the dungeon. A letter from Nightcloak:
On behalf of Domastrus the mighty and Mouringlar the living embodiment of Tiamat, we accept the gift from you on behalf of Verbreen, the fairest Lady of Decay as a further token of our alliance. We will collect the Eladrin bitch as soon as I can arrange suitable escort, undoubtedly within two days.Yours in Decay, -Nightcloak"
The group travelled further into the dungeon and found Queen Shephatiah; they tricked her into thinking they were the envoy sent to retrieve Elwind. With the still hibernating Elwind acquired, the group departed and faced an ambush led by an empowered and fungus covered Nightcloak.
Nightcloak and his gnoll allies gathered the unconscious heroes and delivered them to Queen Shephatiah where they were placed into the same magical hibernation storage that held Elwind only minutes before.