You go into a bookshop and buy If on a Winter's Night a Traveller by Italo Calvino. You like it. But alas there is a printer's error in your copy. You take it back to the shop and get a replacement. But the replacement seems to be a totally different story. You try to track down the original book you were reading but end up with a different narrative again. This remarkable novel leads you through many different books including a detective adventure, a romance, a satire, an erotic story, a diary and a quest. But the real hero is you, the reader.