2070-71. Nearly six decades after Step Day and in the Long Earth the new Next post-human society continues to evolve. For Joshua Valienté it is time to take one last solo journey: an adventure that turns into a disaster. But as Joshua confronts his mortality the Long Earth receives a signal from the stars. Its message is simple: JOIN US. The super-smart Next realise that the Message contains instructions on how to develop an immense artificial intelligence but to build it they have to seek help. Bit by bit they assemble a computer the size of a continent - a device that will alter the Long Earth’s place within the cosmos and reveal the ultimate life-affirming goal of those who sent the Message.

Part of the The Long Earth Series series.