That gave me the confidence to really play it up. Every so often I held out my own hand, as though I was deliberately deflecting something instead of just being unaffected. Once I even stopped and laid my hand on top of the head of a student who seemed to be throwing everything but the kitchen sink at me, to no avail. “Give it up,” I said sweetly to him. “Your pitiful magic can’t harm the likes of me.”

He went pale and fell to his knees.

Finally I reached Teddy, who stood near Granny. “What’s with the Our Lady of Perpetual Smugness routine?” he asked me.

“They don’t seem to know about people who are immune to magic, so Owen thought it would freak them out if they couldn’t affect me.”

“It seems to have worked.”

“Want to play?”

“I might as well. I don’t seem to be doing much otherwise. I’ve warned Merlin and Rod about a couple of things, but they’re way ahead of me. Hey, do you think anyone will write stories and songs one day about this epic fight of good against evil?”

“Not unless you feel like doing it. And it’s more like good against annoying, which is less epic.”

I hung out beside Granny while he stepped into the melee, and I soon saw how I must have looked.

He didn’t have quite the experience with magical immunity that I did, so it took him a while to stop flinching when it looked like something might hit him. Soon, though, he caught on to how protected he was, and then he started showing off with theatrical motions to supposedly deflect the magic. All those years as dungeon master had finally paid off for him. I would have bet he wished Dean hadn’t swiped his old Jedi cloak.

Rod and Granny continued to guard the exit. The terrified reactions of student wizards running back to the battle gave me the impression that Rod had cooked up some impressive illusions. Granny mostly swung her cane and shouted, and I was rather glad I couldn’t hear exactly what she was saying. I was sure they were curses of some kind, but whether they were the magical variety wasn’t quite clear in the chaos.

As absolute proof that Idris had left out a few crucial facts about magic, some of the students swarmed around Merlin. Compared to Owen’s spectacular showboating, Merlin didn’t seem to be doing much of anything. If you didn’t know he was the Merlin, you might have mistaken him for an ordinary old man and very likely our side’s weakest link. It would have been one of the dumbest mistakes you ever made.

Four of the student wizards closed in on us. “Hey, Grandpa,” one of them said. “Aren’t you going to join the fight, or are you just gonna stay here with Grandma and watch?”

“You really don’t want him to join in,” I muttered, too low for them to hear.

“I’m quite enjoying it as a spectator,” Merlin said cheerfully. “This is some of the best entertainment I’ve had in months, even better than the last movie I saw about that young Harry Potter.”

“I guess magic is one of those things that you lose with age, huh, Pops?” another one of the guys said.

I shook my head sadly. Stupid, stupid, stupid, I thought. They were such jerks that they didn’t deserve a proper warning. Merlin waved a careless hand and the whole group immediately turned into little white rabbits. Their noses twitched furiously in what had to be a panic. Granny didn’t help matters by saying, “My gran had an excellent recipe for rabbit stew. I haven’t had it in years.” She hefted her cane as if to club a couple of rabbits. The rabbits hopped away from the scary woman with the big stick, only to run into Owen’s wards, which sent them hopping back to cower and shiver in a circle.

Merlin then turned them back into humans, but they stayed right where they were, nearly catatonic with fright. After that, the rest of the student wizards stayed well away from Merlin, which allowed him to resume watching Owen.

I made my way back across the battlefield to Owen’s side. This time I had to pay more attention to where I stepped than to what was flying through the air. A number of the student wizards were on the ground, either utterly exhausted and magically spent or so bombarded by pixies that they couldn’t move. The attrition in their forces meant Owen wasn’t quite so beleaguered. Now he only had to fight off three guys at a time.

That appeared to be enough, though. It wasn’t my imagination; he really was moving more slowly now. It was completely dark, with only moon and starlight illuminating the park, along with the occasional burst of magical light, but I was sure he looked pale. Even his vast resources had to run out after a half hour or so of this kind of activity.