‘Which you then verified empirically. And what gave rise to that postulate?’

‘In Billy Haven’s backpack we found a notebook, The Modification, a how-to guide for getting botulinum toxin into the New York City water supply. Elegant in the extreme. It was like an engineering schematic, every step outlined, timed down to the minute. I doubted the Stantons and Billy would’ve been able to come up with something that elaborate: a serial killer to misdirect from a plot to target the water supply with bombs, which was in turn meant to cover up the real plot to poison the water. And you learned how to weaponize the toxin. Resistant to chlorine. Quite a coup, that was.’

‘You found the notebook?’ The man sounded displeased. ‘I told Billy to transcribe it into an encrypted digital file on a computer with no Internet access. Then destroy the original.’ A pause. ‘But I’m not surprised. That whole gang from Southern Illinois seemed rather analog. And, yes, not particularly brilliant. Like the toxins Billy decided to use? I recommended commercial chemicals but Billy had this affection for plants. He spent a lot of time by himself in the woods, I gathered, sketching them when he was young. Tough childhood when your parents are killed by the federal government and your moral compass is a neo-Nazi militia.’

‘The Modification? You coined the word?’

‘That was mine, yes. Though I was inspired by Billy’s avocation. Body modifying. It suited their apocalyptic views. I was embarrassed actually. Too on the nose. But they liked the sound.

‘You dictated it to Billy, the whole plan?’

‘That’s right. And his aunt. But Billy wrote it down. They came to visit me in prison. The cover was that Billy was writing a book about my life.’ He paused. ‘There’s a story I’ve been dying to tell but haven’t found the appropriate listener. I think you’ll appreciate it, Lincoln. When I was finished giving him the plan and he’d written it all down, I said, “It’s all yours, Moses. Go forth.” Billy and Harriet didn’t get it. I know you’re familiar with the theological concept of God as a watchmaker.’

When contemplating the origin of the universe, Isaac Newton, René Descartes and others of the Scientific Revolution in the seventeenth and eighteenth centuries argued that design requires a designer. If something as complex as a watch could not exist without a watchmaker, by analogy human life in the universe – far more complicated than a timepiece – surely could not exist without a God.