"If the Great Evil's energy weapon is capable of not only bringing objects from Hell into this dimension, but also corrupting good souls like Vardus', we're all in a lot of trouble. I need time to consider what our next move should be. In the meantime, I've detected several Ghasts in the cavern that would give you a good opportunity to practice your Archery skills. Head inside and kill 10."
As you leave Nichol's house, head toward the stairs that lead to the cavern and walk up to the entrance. Just inside, ghasts will spawn in front of the path. The best way to kill them is shooting them with a bow, but you can also use rocket boots to fly and kill them by using a sword. Once you have successfully killed ten ghasts, return to /warp chapter2.