"I've completed my analysis of the Radioactive Isotopes you brought me earlier. It seems to be the byproduct of the energy being used by CluDathoon's Energy Weapon. I may be able to use this material in the engines of my ship also, but it's going to require further study. In the meantime, my scanners have detected on of CluDathoon's Lieutenants at a base in the area. Find the tunnel South of Ring 15 and follow it to a structure. Once there, find and kill Klimek."
Using your wings and rocket boots, fly to the purple and white rings outside Nichol's house and count them until you reach Ring 15. In the wall next to the ring, there is a large opening. Go through it and fly until you reach the structure. Go inside and defeat Klimek. Once you have done so, return to /warp chapter3.