The Long War. Long Earth 2 - Tapa blanda

A generation after the events of The Long Earth, mankind has spread across the new worlds opened up by Stepping. Where Joshua and Lobsang once pioneered, now fleets of airships link the stepwise Americas with trade and culture. Mankind is shaping the Long Earth – but in turn the Long Earth is shaping mankind ... A new ‘America’, called Valhalla, is emerging more than a million steps from Datum Earth, with core American values restated in the plentiful environment of the Long Earth – and Valhalla is growing restless under the control of the Datum government...
Meanwhile the Long Earth is suffused by the song of the trolls, graceful hive-mind humanoids. But the trolls are beginning to react to humanity’s thoughtless exploitation ... Joshua, now a married man, is summoned by Lobsang to deal with a gathering multiple crisis that threatens to plunge the Long Earth into a war unlike any mankind has waged before.

Terry Pratchett (Author)
Terry Pratchett was the acclaimed creator of the global bestselling Discworld series, the first of which, The Colour of Magic, was published in 1983. In all, he was the author of over fifty bestselling books. His novels have been widely adapted for stage and screen, and he was the winner of multiple prizes, including the Carnegie Medal, as well as being awarded a knighthood for services to literature. He died in March 2015.

Stephen Baxter (Author)
Stephen Baxter is one of the UK's most acclaimed writers of science fiction and a multi-award winner. His many books include the classic Xeelee sequence, the Time's Odyssey novels (written with Arthur C. Clarke) and Time Ships, a sequel to H. G. Wells’s The Time Machine, a Doctor Who novel, The Wheel of Ice, and most recently the epic, far-future novels Proxima and Ultima. He lives in Northumberland.