Master trainer though he was, Evans did not understand that wolf ancestry makes dogs almost unbelievably adept at reading body language. Given the opportunity, they study us endlessly. With Evans's permission, I rigged a free-standing wooden frame with a pull-up shade so I could zero in on Evans's body in increments, looking for an involuntary physical prompt. I finally found a twitch but wouldn't spoil the fun by revealing its location while Dog lived. Sadly, this is no longer an issue.