In the dormitory go a little to the left and at the wood wall look for a
real dark wooden block and press the action button and there it is.

Basilisk Hint

First go into battle with the Basilisk use spells in this order:
Vermildilius Trio, Skurg Trio, and (CC) Blast Curse and Beat it. Then
start a new game on that file and you well be invincible.