He chose the black one. No. He wouldn’t kill the child. Why? Because you don’t just kill a child because someone tells you they are evil. Wolf instinctively knew that was wrong. Who really knows what a child is going to turn into? And again, Wolf wasn’t sure whether he trusted the information he’d been given. It just wasn’t plausible enough. Again, Wolf’s warrior’s mind looked at the actual facts of the situation, rather than the feelings the situation aroused. Would you time travel back to kill so-and-so isn’t a good question, because there is no such thing as time travel. And because no one in the present can accurately predict the future, it is also wrong to kill a child because someone makes a prediction about them. It’s flawed science. He wrote this reasoning, as best he could, in the box on his sheet of blue paper.

The next question was the same, almost, but the voiceover said that there was now a 90 percent chance that the child was going to grow up to commit these crimes against humanity. “Would you kill him now?” As Wolf hadn’t wanted to kill him in the first place, he pressed the black button again. In his box he simply wrote See above.

The next image showed three boys that looked almost identical.

“You know for sure that one of these boys is going to grow up to be the man who will kill millions of people. You have to kill all three of them to be sure to get the one you want. This is your only chance to eliminate this evil man. Do you take it?”

Wolf didn’t have to think about this.

Black button. See above.

The next image was of a town. There were yellow-brick buildings and a park with a sparkling silver slide and bright red swings.

“The boy lives here. You have one nuclear bomb. Do you obliterate his town? You would kill fifty thousand people, but spare the lives of millions.” Again, Wolf didn’t have to think. Although he had to admit he found it sort of interesting where this was going. If you had killed the child originally, then at what point would you reject one of these further options?

Black button. See above.

The next image was of the same concentration camps as before, although this time the voiceover explained that the people imprisoned here were every brown-haired man of the right sort of age and background in the world that you’d been able to find. The evil man was definitely one of these people, but you couldn’t be sure which one. “Do you kill them all?” It asked. “There are approximately a million men here, but in killing them, you would save millions more.”