‘Clearly you wouldn’t want to flee in a situation like this one here: trapped in a station wagon, St. Bernard under the car.’

‘Well what happened with Dougall was that he was walking his bike home from school one day and he saw a greyhound about a block off. A lean, ash-colored animal, being led on an extendable leash by a jogger. The dog didn’t notice him, but the mere sight of it was enough to set off the gears of his fantasy. So MacDougall paused there on the sidewalk while his mind did its thing, working its way methodically through all the familiar steps. He imagined the greyhound spotting him, stopping short. There was the nosing around in the monkey grass and the periodic sidelong glances at MacDougall. The ratcheting tension. Then at last the lunge that breaks the leash, the bark like clockwork. Except now what was different?’

‘The bike.’

‘Right. This time MacDougall had his bike with him, in the fantasy as in real life. And so he wondered: what if I got on this bike? What would happen if I just mounted it and pedaled away? The answer, of course, is that the greyhound chased him. Even as he was looking straight ahead, zooming away on his bike in the fantasy, MacDougall could somehow still tell—as in a dream—that the dog was racing right behind him. He could feel it sprinting on its skeletal legs, keeping perfect pace with the bike. He could even hear the greyhound’s horrible huffing, a choked salivary sound as its whole body heaved to keep up with his machine.’

‘This is miserable.’

‘And remember that back in real life MacDougall was standing frozen on the sidewalk, fantasizing all this. Meanwhile, in the fantasy itself, he was biking away, hightailing it down the middle of the road, which, like a road in a nightmare, was completely empty except for him and his pursuer. So MacDougall knuckled down in the fantasy, leaning into the bike’s handlebars and pedaling harder, waiting for the greyhound to give up the chase.’

‘Why didn’t he just bike home? In the fantasy?’

‘Then what? He’d still have to get off the bike to get inside, and the greyhound would be right there, at his front door. No, all he could do was keep biking and hope that it quit. Note too that stopping the fantasy is not a real option, for him: he can’t simply open his eyes and wake up. The way MacDougall’s mind works, he’s in a kind of trance, an almost obsessive-compulsive trance. Has to answer every branch of the what-if for himself. Every decision entails a consequence, so he’s stuck standing there until he’s ramified the scenario to its likeliest conclusion.’

‘He’s made his bed, mentally, so to speak.’