Krill

1. Presumably, you have used KULCAD on the Winding Stair. If not, proceed no further.
2. The bannister turns into a useful scroll. (What a coincidence!)
3. The scroll contains the IZYUK spell, which allows you to fly.
4. Don't waste time using GNUSTO first, especially since you don't have your spell book. Cast it directly from the scroll.
5. Krill's hideaway is to the east. Be careful!