The Long Earth is the first book in a series by Terry Pratchett and Stephen Baxter. It explores a parallel Earth concept, where humanity discovers a way to access an infinite number of alternate Earths. The story follows Joshua Valiente, a man who can 'step' between these Earths, as he embarks on a journey of exploration and encounters various dangers and mysteries along the way. With its imaginative premise and expansive world-building, The Long Earth offers a thrilling space pirate adventure saga with a unique twist.