Barnes constructs a triangle here, then another one, upended--in this chamber cantata of voices about adultery. Stuart is the stolid, financial-type best friend of the wildly fey and scene-making Oliver, a screenwriter. When Stuart meets feet-on-the-ground Gillian, an art conservator, they fall comfortably into modulated love. On the day they marry, though, Oliver is shaken out of his aesthetic prance-trance by the realization that he too has fallen in love with Gillian--but terribly, passionately, air-robbingly. He tells her so too--and the declared passion (though Oliver keeps away from her physically, a scruple) in quick succession works on stolid Gillian like an earthquake. Soon she's thrown Stuart over for Oliver (they marry, have a child), and it's Stuart's turn to be the devastated outsider in this unfortunate version of Jules et Jim. That film is mentioned more than once here, an overt reference point, along with much else that's French; not even in the wonderful Flaubert's Parrot has Barnes's Francophilism been used so much as strict sidebar to his work. Gillian has a French mother; it's to the French countryside that Oliver and Gillian move eventually; and the book is almost sopping with the literary form Barnes feels most at home with: the epigram. Sections, narrated by the two male principals, usually home in on a wry apercu, a cleverly economical philosophical reflection. Gillian's no-nonsense personality makes for an attractive exception, hers seeming the only true personage here; everyone else is too busy making Chamfort-like asides on the comedié humaine to engage us. Barnes is fun, smart, even wise--but fiction, with its loose tags and sloppy surplus, isn't his specialty. He neatens away its essences.