The Long Utopia - Stephen Baxter, Terry Pratchett

THE SUNDAY TIMES TOP TEN BESTSELLER'Rich in an awe-inspiring sense of wonder' Independent'A hymn to the joys of unfettered world-building' Guardian2045-2059. After the cataclysmic upheavals of Step Day and the Yellowstone eruption humanity is spreading further into the Long Earth, and society, on a battered Datum Earth and beyond, continues to evolve.Now an elderly and cantankerous A.I., Lobsang lives in disguise with Agnes in an exotic, far-distant world. He’s convinced they’re leading a normal life in New Springfield – they even adopt a child – but it seems they have been guided there for a reason. As rumours of strange sightings and hauntings proliferate, it becomes clear that something is very awry with this particular world.Millions of steps away, Joshua is on a personal journey of discovery: learning about the father he never knew and a secret family history. But then he receives a summons from New Springfield. Lobsang now understands the enormity of what’s taking place beneath the surface of his earth – a threat to all the worlds of the Long Earth.To counter this threat will require the combined efforts of humankind, machine and the super-intelligent Next. And some must make the ultimate sacrifice . . .____________________The Long Utopia is the fourth in the Long Earth series.'The Long Earth series deserves a place on the bookshelves of hardcore SF fans and general readers alike' Independent on Sunday