IN THE LIGHT OF WHAT WE KNOW

War can divide friends. But then again, so can peace and all that falls between, the spaces inhabited by this ambitious, elegiac debut novel by Bangladeshi-British writer Rahman.

The unnamed protagonist is a brilliant 40-something math whiz–turned-financier who comes from privilege; his father, a Pakistani physicist, is fond of whiskey, his mother scornful of religious pieties (“[n]ot for her such opiates”). The story, though, turns on his mysterious friend Zafar; raised more modestly, he made a fortune as a derivatives trader yet has apparently acquired enough martial skills along the way to thrash a gang of ill-meaning neo-Nazis in a London mews. Now, as the book opens, he is back in London from a harrowing journey both geographical and metaphysical, his talisman being Kurt Gödel's Incompleteness Theorem (“the world was foolish to ignore it in an age of dogma”), his life a scatter burst of fragments. Rahman’s narrative quickly takes flight, literally, moving from London and New York to Islamabad and Kabul and points beyond as the narrator comes to flourish, oddly, in a post-9/11 world where he and his South Asian compatriots are no longer merely local-color background. Rahman capably mixes a story that threatens to erupt into le Carré–like intrigue with intellectual disquisitions of uncommon breadth, whether touching on the geometry of map projections or the finer points of Dante; the reader will learn about Poggendorf illusions, scads of math and the reason flags fly at half-mast along the way. A betrayal complicates matters, but in the end, Rahman’s is a quiet, philosophical novel of ideas, a meditation on memory, friendship and trust: “Such regrets as I have are few,” says his narrator; “I am not an old man, but even if there had been time enough to accumulate regrets, I do not think my constitution works that way.”

Beautifully written evidence that some of the most interesting writing in English is coming from the edges of old empires.