Room 4B was on the second floor of the academic wing, but it didn't look like any classroom I'd been in.

The furniture had been cleared. The walls were lined with equipment I didn't have names for, metal instruments on hooks, glass tubing connected to sealed containers, a long table with leather straps bolted to the sides that I looked at once and then deliberately looked away from.

The floor had runes etched into it in concentric rings, shimmering faintly blue at the edges. I recognized the ...