31
You grab the scroll and cast Read Magic. As you do, the runes become legible and the page yields its mysteries.
This is a Scroll of Lice Summoning. When used in combat, instead of your turn, large angry lice will appear and swarm around your targets. These lice are relatively harmless, but your foes will be unable to attack for three turns and get -3 to all of their Combat Abilities for that time.
After securing the Scroll, you head back to the beginning of this hallway and choose a new direction at
52.