"You have a few minutes," the Gestapo man says, pulling back a cuff to divulge a hulking Swiss chronometer. Then he invites himself in and begins to pace up and down in front of Rudy’s bookshelves, hands clasped behind his back, bending at the waist to peer at the titles. He seems disappointed to find that they are all mathematical texts—not a single copy of the Declaration of Independence in evidence, though you can never tell when a copy of the Protocols of the Elders of Zion might be hidden between the pages of a mathematical journal. When Rudy emerges, dressed but still unshaven, he finds the man displaying a pained expression while trying to read Turing’s dissertation on the Universal Machine. He looks like a lower primate trying to fly an aeroplane.