his cane chair, drawing patterns in the dust with a stick. A shadow falls across the ground. Someone he cannot see is stealing up behind the old man. Is that a knife agleam in the stranger’s hand? What is this he is seeing? He tries to call out, but no sound emerges. The scene blurs—a door opens, and they step through.
Abdul Karim is trembling. Has he just witnessed his own death?
He remembers that Archimedes died that way—he had been drawing circles, engrossed with a problem in geometry, when a barbarian of a soldier came up behind him and killed him.
But there is no time to ponder. He is lost in a merry-go-round of universes, each different and strange. The shadow gives him a glimpse of so many, Abdul Karim has long lost count. He puts thoughts of Death away from him and loses himself in wonder.
His companion opens door after door. The face, featureless except for the orifice that opens and shuts, gives no hint of what the shadow is thinking. Abdul Karim wants to ask: who are you? Why are you doing this? He knows, of course, the old story of how the angel Gabriel came to the Prophet Mohammad one night and took him on a celestial journey, a grand tour of the heavens. But the shadow does not look like an angel; it has no face, no wings, its gender is indeterminate. And in any case, why should the angel Gabriel concern himself with a humble mathematics master in a provincial town, a person of no consequence in the world?
And yet, he is here. Perhaps Allah has a message for him; His ways are ineffable, after all. Exultation fills Abdul Karim as he beholds marvel after marvel.
At last they pause in a place where they are suspended in a yellow sky. As Abdul Karim experiences the giddy absence of gravity, accompanied by a sudden jolt of nausea that slowly recedes—as he turns in mid-air, he notices that the sky is not featureless but covered with delicate tessellations: geometric shapes intertwine, merge and new ones emerge. The colors change too, from yellow to green, lilac, mauve. All at once it seems as though numberless eyes are opening in the sky, one after the other, and as he turns he sees all the other universes flashing past him. A kaleidoscope, vast beyond his imaginings. He is at the center of it all, in a space between all spaces, and he can feel in his bones a low, irregular throbbing, like the beating of a drum. Boom, boom, goes the drum. Boom boom boom. Slowly he realizes that what he is seeing and feeling is part of a vast pattern.
In that moment Abdul Karim has the flash of understanding he has been waiting for all his life.
For so long he has been playing with the transcendental numbers, trying to fathom Cantor’s ideas; at the same time Riemann’s notions of the prime numbers have fascinated him. In idle moments he has wondered if they are connected at a deeper level. Despite their apparent randomness the primes have their own regularity, as hinted by the unproven Riemann Hypothesis; he sees at last that if you think of prime numbers as the terrain of a vast country, and if your view of reality is a two-dimensional plane that intersects this terrain at some height above the surface, perhaps at an angle, then of course what you see will appear to be random. Tops of hills. Bits of valleys. Only the parts of the terrain that cross your plane of reality will be apparent. Unless you can see the entire landscape in its multi-dimensional splendor, the topography will make no sense.
He sees it: the bare bones of creation, here, in this place where all the universes branch off, the thudding heart of the metacosmos. In the scaffolding, the skeletal structure of the multiverse is beautifully apparent. This is what Cantor had a glimpse of, then, this vast topography. Understanding opens in his mind as though the metacosmos has itself spoken to him. He sees that of all the transcendental numbers, only a few—infinite still, but not the whole set—are marked as doorways to other universes, and each is labeled by a prime number. Yes. Yes. Why this is so, what deeper symmetry it reflects, what law or regularity of Nature undreamed of by the physicists of his world, he does not know.
The space where primes live—the topology of the infinite universes—he sees it in