Step Day: the day a blueprint for a potato-powered circuit is released onto the Internet and everything changes. Thousands of people construct their own device and instantly vanish, travelling “east” or “west” along a chain of Earths in parallel universes. The chain may be endless, and although it’s full of life there are no signs of humanity anywhere. The ease of stepping, at least for most people, creates a land rush and a lawless frontier society as humanity expands into the Long Earth.
Two travellers – Joshua Valiente, a human with a natural ability to step, and Lobsang, a computer who claims to be a reincarnated Tibetan, set out on a journey that will take them over a million Steps to the west. Along the way they meet other Steppers, explorers and colonists, and discover more of the secrets of the Long Earth multiverse. Joshua is ambivalent about humanity, drawn to silence, needing human contact but shy and awkward up close. Lobsang is another HAL 9000 or GERTY, human-ish and apparently caring but alien and difficult to trust.
The novel occasionally feels like the result of a brainstorming session, and indeed the authors did hold such a session at a sci-fi convention along the way. Some interesting limits are placed on Stepping – the device will only work for the human who completed its construction, suggesting that it may have a psychological or metaphysical mode of action. The chain itself, with only two directions of travel, instantly makes the whole concept easy to grasp. Iron cannot be Stepped although iron compounds such as haemoglobin seem to be OK – so every new colony has to set up its own foundry, and guns cannot be transported, at least for about ten minutes until humanity solves that particular issue. This seems to serve as a way of slowing the rate of colonization on each new world, and creating a more interesting narrative.
The Pratchett influence is more subtle, although the characters are very much in his style. I didn’t pick up on any obvious references to Discworld. However, while most parallel Earths are only slightly different from the last, each Step bringing gradual changes in the geography, evolutionary outcome or climate, there are occasional outliers where anything goes – a world dominated by tall forests, a crocodile-infested waterworld, etc. These acquire the name Joker Worlds - as a fan of Pratchett’s early sci-fi novel The Dark Side Of The Sun, this makes me happy.