Pietro Brahe is a young Italian physicist working at an experimental supercollider built in a miles, long ring beneath Geneva. As he takes a rented plane up one morning, he is almost blind-sided from above by another plane, disaster averted by inches. The pilot of the other plane turns out to be Ira Epstein, a German novelist, a modern master soon to win the Nobel but for now having abdicated writing. The relationship in conversation developed by these two has mostly to do with perception, both of them training themselves in complementary ways to see the minutest clarities in reality, be they subatomic particles or the air around a gesture. Accompanying their intellectual flights into the ethers of sensibility and cognitive precision is Gilda, Epstein's mistress, who finds herself drawn to Brahe--but drawn with the same ambiguous decorum, elegance, and tact that the men show each other. Del Guidice, an Italian born in 1940, uses this book as a kind of homage to Calvino (though Epstein has his Norman Mailer-esque side too), and the suavity of understatement and insistence of nuances is moving in that context. The novel has the feel of a good Antonioni movie--superbly attractive people in a time-out-of-mind situation--yet it's even better: Brahe in particular becomes luminous and exciting as his experiments at the end reach a level of the abstract that has caused Epstein, in despair of even reaching it himself, to give up literature. A Mobius-strip novel--but trim, supple, and lucently graceful.