The Long Utopia

It is the middle of the 21st century
After the cataclysmic upheavals of Step Day and the Yellowstone eruption, humanity is spreading further into the Long Earth. Society, on a battered Datum Earth and beyond, continues to evolve.
And new challenges emerge.
Now an elderly and cantankerous AI, Lobsang is living with Agnes in an exotic, far-distant world. He's determined to lead a normal life in New Springfield—they even adopt a child. But there are rumors, strange sightings in the sky.
On this world, something isn't right . . .
Millions of steps away—learning about a hidden family history and the father he never knew—Joshua receives an urgent summons from New Springfield.
Lobsang has come to understand that what has blighted his Earth is a threat to all the worlds of the Long Earth. To counter this threat will require the combined efforts of humankind, machine, and the superintelligent Next.And some must make the ultimate sacrifice . . .

Terry Pratchett (1948–2015) was 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.