Cyjar was on his way to dinner when someone tapped him on the shoulder. He turned, but nobody was there. A ghost? Puzzled, he started walking again. Three strides later, someone tapped his shoulder - this time on the other side. He stopped and took a careful look around.
This hallway ran along the outer wall of the central keep, so there was light from the arrow slits along the left-hand wall in addition to the glow-glasses in their sconces. Glow-glass was created by enchanting regular glass, so it could be made in any shape. In this area of the castle, the glow-glasses had been shaped to resemble flames, and they lined the hall at regular intervals. There was no shortage of light here, and no place for anyone to hide.
There was also nobody else anywhere nearby.
After a moment Caijar shrugged and started walking again. This time, when he felt the touch on his shoulder, he reversed directions and swept his arm out in a wide circle. He felt his fingers brush across something (it felt like cloth) and heard a sudden intake of breath.
A moment later Morius was standing beside him.
Cyjar took a quick step back, raising his arms to a fighting position. Morius wasn't going to attack him, so he didn't really need to defend himself; but having someone appear out of empty air beside him was startling enough that it took a moment for the recognition of his friend to catch up with Cyjar's initial, startled response. As soon as it did, he put his arms back down.
Morius looked apologetic. "I'm sorry," he said. "I've been studying illusions, and the best way to practice is to try them out on people who aren't expecting them."
"Well," said Cyjar, adopting a tone of careful judgement that sounded as much like their teacher, Master Barigil, as he could manage. "I trust you've learned a valuable lesson about the effectiveness of illusion magics: they work far better if you don't go around touching people when you're trying to remain unseen."
Morius grinned. "A valuable lesson indeed. I shall mark it down in my notes, alongside the one that says, 'Never be late for dinner'."
Exasperated, Cyjar asked: "Well, whose fault is that?"
"Not mine," said Morius. "Not if we hurry."