She turned to me. "I thought you said you had a way to get me off the hook," she protested. "How are we—?"
"Quiet," I told her. "I didn't come up here for a lecture in logic. Especially from a dumb blonde." She started to bristle, but thought better of it.
"It goes like this, Prof," I said. "This innocent looking piece of fluff was caught slipping a five-dollar bill to a teller at a bank down town, and asking for change for a hundred dollar bill. She says it was nothing more than sleight of hand. You are an experienced observer. I want you to watch her work her little trick. If she can fool us, and not use Psi, the legal position is that she didn't need Psi to fool the teller." I turned to her. "And the logical principle, Miss Aristotle," I told her, "is equally simple: Occam's Razor. Prefer the simpler explanation. Can you show us how you palmed the hundred and slipped the teller a five?"
"You'll be watching for it," Mary protested, letting those ripe lips pout.
"I suppose the teller wasn't? It's his business to watch the bills when he's making change." I took out my wallet and handed her a one and a five. "Hand me the one and make me think it's the five," I said.
Lindstrom leaned his elbows on the black composition top of the lab bench, watching her narrowly. Mary got down off her stool and came over closer to me, smoothing the two bills in her fingers. The five was on top.
"I'd like change for a five," she said, handing it to me. She worked it three times while we watched.
"Utterly smooth," Lindstrom said. "I didn't see her make the switch."
"Me, too," I agreed. I could see the tension drain from Mary's face. She was prettier when she wasn't worried. She was pretty all the time, when you got right down to it. No wonder she could fool a teller. He probably hadn't taken his eyes off that dazzling smile.
"Is that all?" Lindstrom asked.