Looking in her mailbox one day, a fourteen-year-old Norwegian schoolgirl called Sophie Amundsen finds two surprising pieces of paper. On them are written the questions: 'Who are you?' and 'Where does the world come from?' The writer is an enigmatic philosopher called Albert Knox, and his two teasing questions are the beginning of an extraordinary tour through the history of Western Philosophy from the pre-Socratics to Sartre. In a series of brilliantly entertaining letters, and then in person (with his dog, Hermes), Albert Knox opens Sophie's enquiring mind to the fundamental questions that philosophers have been asking since the dawn of civilisation. But as soon as Sophie begins to find her feet in this dazzling, exciting new world, she and Albert find themselves caught in a plot which is itself a most perplexing philosophical conundrum.