"I've collected a lot of data from the items you've retrieved for me. CluDathoon's weapon seems to be capable of altering the molecules of living beings. The enemies you've encountered here also seem to have special abilities, which I'm sure you've noticed. CluDathoon might be using his weapon not just to kill, but to create an army of enhanced monsters to do his bidding. I'd like to do a little more research - I've detected some Contaminated Ghasts around the building where you killed Klimek. Find them, and bring me 5 x Contaminated Ghast Tears."
Using your wings and rocket boots, fly to the purple and white wings and count them until you reach Ring 15. Fly through the entrance within the cavern wall by the ring and fly until you see the structure. To the right of the structure, locate the spawner and land next to it, where Ghasts will start spawning. Kill as many Ghasts as you need to in order to obtain 5 Contaminated Ghast Tears. Once you have done so, return to /warp chapter3.