“So do I; I’d love to meet him some day.” Owen shied from trying to imagine it, poor beaten-down Floyd Mackenzie with his tender stomach and penny-ante job, and this cosseted Cambridge princess. It would make a meeting as awkward and painful as the one between his mother and Elsie. Our parents hatch us but cannot partake of our work in the world. Phyllis explained to him, trying to give of her deeper self, “Don’t you find it so beautiful, math? Like an endless sheet of gold chains, each link locked into the one before it, the theorems and functions, one thing making the next inevitable. It’s music, hanging there in the middle of space, meaning nothing but itself, and so moving, Owen.” Did he need this nudge? Had he been falling asleep beside her long, soothing body? True, he relaxed when with her, as if home at last. “It used to make me cry,” she said, “when I was a teen-ager, having a problem come apart for me—the way it cracks open at a certain point, goes from being all outside to all inside, if you believe the equations and follow through on them. It’s like, at the beach, turning a horseshoe crab upside down, all the little legs wriggling and the tail flipping to turn it all over. No, my parents didn’t encourage me. They thought science was for plodders, grubby guys usually from the Midwest. I tried to tell them, math doesn’t do useful work, it does useless work. Which of course isn’t exactly true; physics and technology depend on calculus. And set theory.”

“Do you understand,” he asked her—and such a question must have demanded a more intimate setting than a corner, however dimly lit, of the visitors’ lounge at 120 Bay State Road; it might have been in her Bexley Hall room, against the rules, on one of those weekends when her roommate, Sally Fazio from Providence, was back in Rhode Island or off skiing in New Hampshire—“set theory? I mean, why it’s so wonderful?”

“I think I do. It is wonderful, so elemental and original. It’s one man’s invention, you know. Newton and Leibniz invented calculus independently, Lobachevsky and Bolyai did the same for non-Euclidean geometry, and if they hadn’t Gauss would have—it was just sitting there waiting to be picked up—but without Cantor set theory might not have ever come into being. Hilbert said nobody will ever expel us from the Paradise Cantor created. Isn’t that nice? To create a Paradise nobody will be expelled from?” Talking of mathematics, Phyllis became more animated and precise—quicker-voiced, wider and more reckless in her gestures. Her blood ran faster beneath the thin fair skin.

“It is,” he had to agree.

“And he did it, a lot of it, in a mental hospital. His brain snapped, set theory was so powerful.”