All of the stairs going up ask that you identify yourself as a friend. The only two words I've found that work are Hawkslayer and Alendar 
The monster at 9n/1e guards the entrance to the Grey Tower. To get rid of him, cast: INWO, WIHE, FOFO and INVI. 
To get rid of the wall at 0n/10e (blocking the Black Tower), cast MAFL, SHSP, FEAR, SUEL and SPBI. 
The magical curtain at 9n/10e blocks off the entrance to the White Tower. To get rid of it, cast: LEVI, ANMA and PHDO. 
The disk at 9n/4e leads to the Ice Dungeon. To open it, use the three lenses (smokey, black and white) at that location. 
