Any sap can have a bad marriage, but some unions rise above the masses to become classics of dysfunction. Similarly, many novels claim to show us the dark heart of modern marriage, but only a few pull it off with real panache. Being a newlywed is fun for those involved, but you only really become interesting to neighbours, and readers, when it all starts to unravel. Who cares about a beautiful Home Counties bride happily signing over her best reproductive years in a tasteful frock, when you could be reading the history of a disappointed couple throwing insults and gin tumblers at each other after a dinner party? Of course, there's always the hope one will lead inexorably to the other. There is perverse beauty in marital breakdown, and writers who show us this, from Henry James to John Updike, are worth celebrating.