Now, extraordinarily, Sarah Waters has leap-frogged a host of more commercial candidates within the top 10 to take first position, launching herself into the premier league of British literary fiction writers. Waters’s success may owe something to television dramatisations of two of her earlier books, Tipping the Velvet and Fingersmith, but the novel (her fourth, and the first set outside the Victorian era) has also been receiving rave reviews. Waters admitted recently that writing the book had been agony — “For the first two and a half years it was awful,” she confessed. “I was in tears.” This weekend, one suspects, all those creative pains will be forgotten.