Every one had started the same way: with Isaac slashing the toe of his shoe, or the point of his stick, across the ground to make a curve. Not a specific curve – not a circle or a parabola – but a representative curve. Everything in the universe was curved, and those curves were evanescent and fluxional, but with this gesture Isaac snatched a particular curve – it didn't matter which – down from the humming cosmos, like a frog flicking its tongue out to filch a gnat from a swarm. Once trapped in the gravel, it was frozen and helpless. Isaac could stand and look at it for as long as he wanted, like Sir Robert Moray gazing at a stuffed eel in a glass box. After a while Isaac would begin to slash straight lines into the gravel, building up a scaffold of rays, perpendiculars, tangents, chords, and normals. At first this would seem to grow in a random way, but then lines would intersect with others to form a triangle, which would miraculously turn out to be an echo of another triangle in a different place, and this fact would open up a sort of sluice-gate that would free information to flood from one part of the diagram to another, or to leap across to some other, completely different diagram – but the results never came clear to Daniel's mind because here the diagram would be aborted and a series of footsteps – lunar craters in the gravel – would plot Isaac's hasty return to his chambers, where it could be set down in ink.