The Long Earth, by Terry Pratchett and Stephen Baxter, tells the story of the expansion of humanity into a seemingly endless collection of Earths. When plans for the “stepper” – a box of simple electronic components powered by a potato – appears on the internet, it seems little more than a harmless project for children. However when children disappear on “Step Day” the device ushers in a new era for humanity. The dwindling space program is soon replaced with a colonial movement comparable to the that of the Old West. However, this expansion is on a much grander scale, an expansion into the multiverse – where alternate evolutionary scenarios play out for each Earth and all its abundant lifeforms – with the notable exception of man.

The main character, Joshua, had lacked something his entire life. As a natural “stepper” – someone who could “step” into alternate worlds without a box – he had always felt at odds with his fellow humans. However, as he follows humanity’s expansion across the multiple earths and beyond, he witnesses changes across the worlds and must face the foreboding he feels as he travels ever “westward.” Yet the book lacks the focus of a protagonist with a clear goal, someone and something to root for.

The science throughout the book was interesting, allowing readers to explore the alternate Earths along with the characters. Aside from the ridiculous premise of the potato-powered stepper, the evolutionary biology seems well thought out and we get the sense we’ve only seen the tip of the iceberg.

Socially, economically, and politically, humanity must deal with suddenly limitless resources while coming to grips with their place in a universe must larger than they ever dreamed. Some react well. Others don’t. New and interesting characters are introduced and situations set up.

However, those new and interesting characters and situations barely get a chance to pay off before the book ends. While the prose was well written, the majority of pages never focus on anything other than the general “westward” expansion. Ninety percent of the story is world building. The plot only focuses and becomes truly compelling in the last thirty to forty pages. The entire novel felt like the prologue to a series rather than a story in its own right – a fact further emphasized by its ambiguous ending.

Furthermore, Pratchett fans may be disappointed by the book’s style – serious and devoid of the Disc World’s light-hearted humor. However, the prose is clear and straight-forward. The concepts and worlds are introduced in a way that is easy to follow.

While the science was interesting, with even the ridiculous stepper having a hypothesized rational explanation, by the novel’s end there was not enough of a payoff to justify the buildup. While this might work as part of a larger story, it fails to have a satisfying ending of its own. The book merely stops by introducing more questions than answers – a fact that, had I known, would have deterred me from my purchase. After over three hundred pages of a promising and ambitious premise, the ending ended nothing and left this reader unsatisfied.