Martin Gilmour is an outsider. When he wins a scholarship to Burtonbury School, he doesn't wear the right clothes or speak with the right kind of accent. But then he meets the dazzling, popular and wealthy Ben Fitzmaurice, and gains admission to an exclusive world. Soon Martin is enjoying tennis parties and Easter egg hunts at the Fitzmaurice family's estate, as Ben becomes the brother he never had. But Martin has a secret. He knows something about Ben, something he will never tell. It is a secret that will bind the two of them together for the best part of 25 years. At Ben's 40th birthday party, the great and the good of British society are gathering to celebrate in a haze of champagne, drugs and glamour. Amid the hundreds of guests - the politicians, the celebrities, the old-money and newly rich - Martin once again feels that disturbing pang of not-quite belonging. His wife, Lucy, has her reservations, too. There is disquiet in the air. But Ben wouldn't do anything to damage their friendship. Would he?