Perfect Rigour, By Masha Gessen

Strange and fascinating, this is the story of Grigori Perelman, the Russian maths genius who solved a century-old puzzle called the Poincaré conjecture in 2006.

Like Fermat's theorem, it is a bit tricky for non-maths geniuses to get a handle on, though Gessen does her best. It is to do with the three-dimensional topology of the manifold or, as Gessen helpfully explains, a bagel when viewed in four dimensions.

Perelman refused all bouquets including mathematics' top honour, the Fields Medal. He emerges as a troubled man, shunning human contact. Yet his explanation, through an intermediary, for rejecting a $1 million prize from American businessman Landon Clay is rather magnificent: "Clay is a nothing from his point of view – why take his money?"