In focault, north end of the gallery then north. Need a key from focaults chest to get there or have a second classer kill Klemanak, the Conjurer and pull the lever in that room (1 alyrian month cooldown)
From marble bust of enchanter Cymeneth:
N, N, E, E, D, W, U, U, S, E, E, N, N
If you are in his room when he respawns he will shove you into an NPK death trap.