Adrien followed the sorcerer Valerion to the north tower - past the first door, up another set of spiral staircases, and past a second wooden door.

The room beyond this door was octagonal, just like the large room downstairs and like the room in which he had slept; but, unlike both, this other room was completely barren - all walls, floor and ceiling, like a strange stone cage. There was a lone window on one of the walls and torches on some of the others - they had lit themselves upon opening the door.

"Welcome", Valerion said, as his voice bounced off the empty walls, "to the practice tower". Noticing Adrien's puzzled expression, he added: "The reason why it is empty is so that you can freely draw your spells all over the walls and the floor. Today, you will draw on the wall".