I pulled the curtains shut and started on my oval of glass. I knew the spells now, and everything went smoothly. As I stood at the edge of the river of magic, I knew exactly what to say, to have my mind control the spells without ever endangering myself.

At the end I opened my eyes. “On. Out.” The piece of glass obediently shone out with a brilliance far beyond what I had expected, then darkened again. This, I thought, would make a remarkable improvement in the chapel stairs. I hoped Joachim would be suitably grateful.

“On,” I said again, reaching for the curtains. My belt buckle lit up, but the glass stayed dark. I tried again, changing the modulation of my voice, but nothing happened. I tried probing the spell attached to the glass with my mind, but there was no magic there at all.

I sat down. Somehow I must not have attached the spell properly, so that it had withered and returned to the deep channels of magic as most spells do. But I could not see where I had gone wrong. Magic really should work all the time if the wizard does it correctly.

I shook my head, then shook my shoulders as well, dispelling the chilling unease that suddenly gripped me. I would try again.

This time there was no problem at all. I threw open the windows and opened the door to my bedroom, where I had taken my predecessor’s magic lights so they wouldn’t come on and break my concentration.

The spells had taken all morning. I tucked the oval of glass under my arm, planning to show the constable at lunch. I would let him find a way to attach it to the ceiling in the staircase. My predecessor might have been able to make his lamps hang suspended in the air, but at this point I thought glue would work just as well.