It’s unusual to get a science-fiction novel that was also longlisted for the Booker, as this was. The question, though: is it science fiction?

It certainly has science: most notably marine biology. Also space travel to the edge of the solar system via a new, unexplained drive; something which might be a first contact event; possible time travel; and a kind of ascendence. In fact there’s a section near the end that had strong resonances of 2001: A Space Odyssey for me.

So yes, it’s SF. But it feels somehow incomplete. Not unfinished, except in the way you might say that about 2001 itself. It keeps the pages turning OK, but I’m not entirely sure exactly what it’s trying to achieve, and (therefore) whether it’s successful.

It tells two stories at once. And I do wonder whether MacInnes was similarly torn between his desire to write a mainstream, literary novel, and one diving deep into fantastika.

Leigh, the marine biologist who ends up on a space mission, had a physically abusive father, which not surprisingly affects much of her life. Though her sister appears not to have suffered similarly, and there are hints that Leigh is not entirely a reliable narrator. (But then again, who is?) The adult Leigh is torn between her career and her desire to visit her mother, who is showing signs of dementia.

As a marine biologist Leigh experimentally engineers algae which is intended to feed, oxygenate, and cheer up the small crew of a year- (or more) long voyage. But there’s a lot going in the background of the story, that Leigh and most of the other characters are not privy to. Secrets kept by companies and governments. We, the readers, are also kept outside the walls of secrecy.

So it’s very good at evoking the situation of someone who is a cog — albeit an essential one — in very complex machine, but who has no picture of the machine as a whole.

All of which leaves it convincing, but frustrating, especially if you’re looking for a nicely wrapped-up story.