John Banville’s new novel revolves around a fictional painter called Oliver Orme, who was once well known but has suffered an artistic crisis and has now abandoned painting.  He has, however, maintained his enthusiasm for his second career, as a thief.  But Oliver’s thieving is itself a kind of ­performance art.  It demands an audience.  He therefore sets about stealing things that lack utility or monetary value, but which ­people will nonetheless notice when they ­mysteriously go missing.Perhaps his most significant theft is that of his best friend’s wife, with whom Oliver begins an affair. Yet the initial thrill of this relationship evolves into something more melancholic, and the novel ruminates on the other kinds of losses that occur t