This is from the quest "the Dungeon Rot Infected" from Skal Nethus in Plane of Knowledge.
deliver 1 dungeon rot spores of Upper Guk to Skal nethus
deliver 1 dungeon rot spores of solusek to Skal nethus
deliver 1 dungeon rot spores of crystal to Skal nethus
deliver 1 dungeon rot spores of kaesora to Skal nethus
deliver 1 dungeon rot spores of lower guk to Skal nethus
deliver 1 dungeon rot spores of stones to Skal nethus
deliver 1 dungeon rot spores of nadox to Skal nethus
deliver 1 dungeon rot spores of ssraeshza to Skal nethus
deliver 1 dungeon rot spores of thunder to Skal nethus
deliver 1 dungeon rot spores of zek to Skal nethus
deliver 1 dungeon rot spores of vergalid to Skal nethus
deliver 1 dungeon rot spores of zhisza to Skal nethus
deliver 1 dungeon rot spores of toskirakk to Skal nethus
deliver 1 dungeon rot spores of kaesora library to Skal nethus
????
search for creatures infected by Dungeon Rot in Upper Guk, Solusek's Eye, the Crystal caverns, Kaesora, Lower Guk, the Howling Stones, the Crypt of Nadox, Ssraeshza Temple, the Bastion of Thunder, the Fortress of Zek, the Vergalid Mines, Zhisza, Toskirakk, and Kaesora Library.
reward:
786 platinum, 5 gold
you gain experience!!
Purified Dundeon Rot