He leaned his hands on his desk and regarded me, eyes sparkling. "I know how wizards live forever." He paused for a thoughtful second and then said, "Wait, that's six words. Never mind, then. What did you want to talk about?"

My mouth fell open. I shut it and glared at him. "No one likes a wiseass, Butters."

He grinned. "I told you it was important."

"Wizards don't live forever," I said. "Just a really long time."

Butters shrugged and kept pulling out file folders. He flicked on a backlight for reading X-ray films, and started pulling them from the folders and putting them on the light. "Hey, I'm still not sure I buy into this whole hidden-world-of-magic thing. But from what you've told me, wizards can live five or six times as long as the average human. That's closer to forever than anyone I know. And what I've seen makes me think there must be something to it. Come here."

I did, frowning at the X-rays. "Hey. Aren't these mine?"

"Yep," Butters confirmed. "After I switched to one of the older machines, I got about fifteen percent of them to come out," he said. "And there are three or four from your records that managed to survive whatever it is about you that screws up X-rays."

"Ugh. This is that gunshot wound I got in Michigan," I said, pointing at the first. It showed a number of fracture lines in my hip bone, where a small-caliber bullet had hit me. I had barely avoided a shattered pelvis and probable death. "They got this one after they got the cast off."

"Right," Butters said. "And here, this is one from a couple of years ago." He pointed at a second shot. "See the fracture lines? They're brighter, where the bone re-fused. Leaves that signature."

"Right," I said. "So?"

"So," Butters said. "Look at this one." He flipped up a third X-ray. It was much like the others, but without any of the bright or dark lines. He flicked it with a finger and looked at me, eyes wide.

"What?" I asked.

He blinked, slowly. Then he said, "Harry. This is an X-ray I took two months ago. Notice the lack of anything wrong."

"So?" I asked. "It healed, right?"

He made an exasperated sound. "Harry, you are dense. Bones don't do that. You carry marks where they re-fused for the rest of your life. Or rather, I would. You don't."

I frowned. "What's that got to do with wizard life span?"

Butters waved his hand impatiently. "Here, here are some more." He slapped up more X-rays. "This is a partial stress fracture to the arm that didn't get shot. You got it in that fall from the train a couple nights after we met," he said. "It was just a crack. You didn't even know you had it, and it was mild enough that it just needed a splint for a few days. It was off before you were ambulatory."