The Long Earth

Joshua Valienté, a quiet young man who grew up in an orphanage, turns out to be a natural stepper who can move between worlds without a device. He is recruited by Lobsang, a mysterious and talkative artificial intelligence, to travel on an airship farther along the Long Earth than anyone has gone before. On the way they meet other travellers, strange creatures and humanoid beings, and they notice that something seems to be driving them away from the distant Earths.

Meanwhile, the original Earth changes dramatically: people leave cities to settle new worlds, economies are shaken, and those who cannot step feel left behind and resentful. The novel combines Pratchett's warmth and wit with Stephen Baxter's careful science-fiction ideas. It is more a journey of discovery than a tightly plotted thriller, with many side stories, and some readers find the pace slow, while others love the sense of wonder.

Imaginative, curious and humane, the first of five books in the series, followed by The Long War. It suits readers who enjoy speculation and exploration more than fast action. About 432 pages in the Harper mass-market paperback.