This encyclopedic novel--about Britain's relationship to the wider world, borders and their conflicts, the body and its passions, and ultimately about imagination--takes place in the mind of Celestine, an English woman on holiday. As she walks the length of Offa's Dyke, the ancient earthwork that divides England and Wales, she ruminates, sometimes comically, on her childhood in India, her sojourns in Jerusalem and New York, her travels in Zimbabwe, and her ruined love affairs. Frequently she ponders characters and passages from books, until at a pivotal moment she finds herself unable to stop reciting Lewis Carroll's "The Hunting of the Snark," which takes on an ever-increasing and sinister significance.