Kristof slid onto center ice, arms up as he pirouetted in his street shoes. I bit back a laugh.

“Test number one,” he yelled. “How can you tell I’m a ghost?”

“’Cause you’re standing in the middle of a frigging ice rink wearing loafers and a golf shirt, and no one’s yelling, ‘Hey, get that crazy bastard off the ice!’”

He grinned and shoe-skated over to the boards. When he reached the gate, he grabbed the edge with both hands and jumped. Fifteen years ago, he could sail right over it, even in full hockey gear. Today, well…

“Hey, at least you cleared it,” I said as he got up off the floor.

“You know, I hate to complain,” he said, brushing invisible dirt from his pants. “The Fates take away all those twinges and aches of middle age, and that’s great, but would it kill them to give us back a little flexibility?”

I kicked one leg up onto the top of the boards. “Seems fine to me.”

A mock glower. “No one likes a show-off, Eve. And, I could point out, if I’d died at thirty-seven, instead of forty-seven, I’d have been able to do that, too.”

“A good excuse.”

“And I’m sticking with it. On to test number two.”

Before I could object, he jogged into a group of parents hovering around the boards.

“How can you tell I’m a ghost now?” he called.

“Because you’re walking through things. I know all this, Kris. It’s common sense. If I want a ghost to mistake me for a corporeal being, then I have to act corporeal. When I passed by that group of people outside the hospital, I moved around them.”

“Ah, but you missed something. Last demo. Professional level now.”

He bounded up a half-dozen steps, then walked into a bleacher aisle. As he slipped past people, he was careful to make it look as if he were squeezing around their knees, even murmuring the odd “Excuse me.” Halfway down he turned and lifted his hands expectantly.

I shook my head. “You would’ve fooled me.”

“Only because you’ve never gone haunting. Haunters have to be extremely careful. Bump into the wrong ghost, and you’ll be reported in a heartbeat. Now I’m going to try it again, and this time don’t watch me. Watch them.”

He came back my way, still skirting knees and whispering apologies. I watched the faces of those he passed, but saw nothing. They just kept doing what they were doing, acting—

“Acting as if you aren’t there,” I said. “That’s it. They don’t react to you.”

“Correct,” he said, jogging down the steps. “At that hospital, you walked past a group of people, and not one even glanced your way. That isn’t natural. Especially if any of them were male.”