Thirteen-year-old Martin and his younger brother Charlie are on a very special journey. They're going to be travelling 421 miles all the way from Preston to the very tip of Cornwall. By train, bus and taxi, they are determined to get there in the end; and they're hoping to catch a glimpse of the dolphin that regularly visits the harbour there. But is that the only reason they are going? An unforgettable novel that is by turns funny and heartbreaking.