The Long War (Long Earth, 2)

The Long War by Terry Pratchett and Stephen Baxter follows the adventures and travails of heroes Joshua Valiente and Lobsang in an exciting continuation of the extraordinary science fiction journey begun in their New York Times bestseller The Long Earth.
 
A generation after the events of The Long Earth, humankind has spread across the new worlds opened up by “stepping.” A new “America”—Valhalla—is emerging more than a million steps from Datum—our Earth. Thanks to a bountiful environment, the Valhallan society mirrors the core values and behaviors of colonial America. And Valhalla is growing restless under the controlling long arm of the Datum government.
 
Soon Joshua, now a married man, is summoned by Lobsang to deal with a building crisis that threatens to plunge the Long Earth into a war unlike any humankind has waged before.

Terry Pratchett (1948–2015) is the acclaimed creator of the globally revered Discworld series. In all, he authored more than fifty bestselling books, which have sold more than one hundred million copies worldwide. His novels have been widely adapted for stage and screen, and he was the winner of multiple prizes, including the Carnegie Medal. He was awarded a knighthood by Queen Elizabeth II for his services to literature in 2009, although he always wryly maintained that his greatest service to literature was to avoid writing any.

Stephen Baxter is an acclaimed, multiple-award-winning author whose many books include the Xeelee Sequence series, the Time Odyssey trilogy (written with Arthur C. Clarke), and The Time Ships, a sequel to H. G. Wells's classic The Time Machine. He lives in England.