“Exactly. But killing you would have fulfilled my destiny. All that remained after that is for Goliath to train up the other Gavin Watkins. Brainwash him, pay him off, coerce him— whatever it takes—to murder all those ChronoGuard. My future self was leaving provision to save everyone, and the future Goliath was doing all they could to thwart me. And they almost succeeded.”

There was a pause.

“Okay,” I said, “just supposing all this does make sense, where is the other Gavin Watkins? And how can you kill him three minutes ago?”

“Given the timescale,” said Friday, “only one possible place.”

“Liddington,” I murmured.

“Right,” said Friday, “all that ‘Swindon Time Zone’ nonsense means that only Liddington is running on Swindon time—and that’s seven minutes behind Greenwich. I’ve got”— he looked at his watch—“three minutes and eight seconds to find him. And you know what? I will. It’s my destiny—and his. Tuesday? We need an address.”

He ran out the door, and I ran with him, and within a minute we were on the road back into town. Tuesday rang me with an address as we drove past the signs declaiming cartographic independence on the edge of the village, and I gave Friday the directions. A few moments later, we screeched to a halt before an ordinary-looking house. Friday jumped out, ran up the garden path and opened the front door with myself close behind. We found a young man of no more than eighteen, standing in the hallway reading his mail. There was a suitcase on the floor; it looked as though he had just returned from a trip.

“Gavin Watkins?” said Friday, glancing at his watch. I checked, too. There was one minute and twenty-six seconds to go.

“Yes?”

“My name’s Friday Next, and I’m going to kill you.”

“Ah,” said Liddington-Gavin, showing us his freshly opened Letter of Destiny, “I’ve just been reading about you. Why has that woman only got one arm?”

“It’s a long story,” I said.

Friday explained what he had to do and why he had to do it as the other Gavin Watkins listened quietly. Friday told him about the murders that Gavin would commit and that Friday was sacrificing his own freedom but saving the murdered ChronoGuard, 7 billion people and an agreeably pleasant yet somewhat taken-for-granted blue planet. When he had stopped, there was a pause. Gavin looked at Friday, then at the gun he was pointing at him, then at the clock.

“But you can’t and won’t,” he said with a smile, waving his life summary at us. “According to this I marry your sister and have three children with her. We go on to do great works together—seriously good science—and I become one of the greatest mathematicians of my generation. I don’t die now—I die in my sleep aged ninety-four in 2082.”

“Sure you do,” said Friday. “Good at math are you?”