I have successfully completed the quest for Kelnar in the Tower, and have dispatched the Demon in the upper room. Kelnar has given me the key, and I have gone into the room nearby to consult his magic book, only to be told it is "not decipherable". My Mage is level 11. It appears this is the only place I can acquire the Dispel Barrier spell, and that this is essential to complete the rest of the game. Any help will be appreciated.