Interstellar polities without Faster-Than-Light travel are not especially common in science fiction. Four examples spring to mind: Ursula K LeGuin’s Ekumen novels and stories, William Barton’s Dark Sky Legion, Chris Moriarty’s Spin State and sequels, and Alastair Reynolds’s Revelation Space series. And now Carolyn Ives Gilman’s Twenty Planets, in which people and materials are sent as beams of light from world to world and so experience time dilation from travelling at lightspeed. Scientists and explorers who regularly do this form “a strange sodality out of time”, and are known as “Wasters”.

Saraswati Callicot is one such Waster, an exoethnologist. Returning to Capella at the end of a five-year mission – but twenty-three years have passed on Capella – she is promptly recruited by an old mentor to join a team studying a newly-discovered planet fifty-eight light years away. The world is crystalline, so unlikely to be habitable; but it is also in a region of space containing “an odd concentration of dark matter”. Ostensibly a part of the team to research its new management techniques, Sara will actually be keeping an eye on a relative of her mentor, a woman called Thora who has only recently recovered from traumatic events on another world.

A handful of days after Sara’s arrival, one of the security guards aboard the scientists’ ship is murdered, and then Thora disappears during a trip to the planet’s surface. She has been taken by humans who live underground in lightless caves and are entirely blind. They also perceive their world – including the waves of dark matter which frequently pass through it – in a unique way. The natives speak a slightly archaic form of English, evidence they have been cut off from the mainstream of human history for a considerable time. Unfortunately, the presentation of this argot is not entirely successful, and makes it somewhat hard to take them seriously. However, life in the cave, and the solutions its inhabitants have put in place to in response to the absence of light, are ingenious and well-described. Gilman captures the claustrophobia of Thora’s stay there very effectively.

As Thora explores Torobe, the cavern village in which she is staying, she realises the villagers possess strange abilities which seem to contradict known science. The Torobians talk of visiting other settlements, yet their talk suggests they travel to other worlds and meet other races. It is through Thora’s friendship with Moth, a teenage girl from Torobe, that the central conceit of Dark Orbit is eventually revealed. In part, Thora’s ability to understand this premise is a consequence of the trauma she had experienced previously. This we learn from Thora’s journal, which forms a second narrative interwoven with Sara’s.

Thora’s discovery that the universe and its laws are a consequence of perception – albeit not a solipsistic universe per se – and that the Torobians’ blindness allows them to “manipulate” their reality, initially seems a bit wobbly for suspension of disbelief. But while attempting to duplicate the Torobians’ ability to “wend”, or travel instantaneously, even across interstellar distances, Thora realises, “Maybe it can’t be observed, because if you observe, you prevent it”. The Observer Effect, in other words. In quantum mechanics, the act of observation causes a wave function to collapse – so it seems plausible an absence of observation would suggest the laws of physics are a consequence of perception.

The scientists are obviously sceptical of Thora’s report on the Torobians’ abilities. She in turn is scared what use Capella’s corporations would make of the knowledge. But when a dark matter event damages a vital component in the lightbeam equipment aboard the scientists’ ship, Thora successfully wends to Capella to fetch a replacement.

One other aspect of Dark Orbit deserves mention: the Twenty Planets are multi-racial and multi-cultural, and relations between these are handled with sensitivity and nuance. There is none of the white monolithic universes of last century’s science fiction.

Dark Orbit is a fast read, but a substantial one. The central conceit may at times feel like borderline nonsense, but Gilman manages to keep suspension of disbelief in place for the length of the novel. This is a novel that would not look out of place on an award shortlist or two next this year.

This review originally appeared in Interzone #259, July-August 2015.