Book Review: In Ascension

May 31, 2024

I read In Ascension in March 2024, and at the time I wrote down quite a few thoughts about the book because I enjoyed it so much. I'm now revisiting my notes to attempt to turn them into a coherent review of the book. Note: I've tried to keep the review section fairly spoiler-free, but there is some discussion of the pacing and characterisation. The subsequent two sections - questions and theories about the book - are full of spoilers!


First and foremost, I found In Ascension very compelling. I read most of the book in a couple of sittings, and found it difficult to put it down. For me, this is an increasingly rare experience as I've grown older, and the internet has rotted my attention span, so I always value it very highly.

A way that In Ascension stood out for me from other sci-fi that I've read recently was the level of mystery. Science fiction often loves an explanation, and I think a mark of good sci-fi for me is getting the right balance of what's explained and what's implied. When a book is written well, concepts can be introduced tangentially and explored in their interactions with the characters and plot. In Ascension took this to an extreme, where some of the ideas remain a mystery (at least to me) throughout the novel. This could have been frustrating in a less well-constructed book, but it worked very effectively with the pacing and plot - it felt like the mysteries and level of understanding I encountered as a reader were mirrored by the protagonist. It wasn't that the book was failing to explain things that the characters knew, but rather that there were things that couldn't be known to the characters or the reader, because they were so strange.

To return to the pacing - one of the most effective aspects of In Ascension for me was the gradual escalation of risk and strangeness throughout the story. For me, there was a sense of connectedness and seeming inevitability that built both within the plot, and the writing itself. By the denouement, it felt like everything in the book was rushing and growing to the point of conclusion. This was partly offset by a change in perspective late in the novel, but I'm sure this was deliberate - the pulling of the punch, so to speak, just added to the idea that there are some things that can't be known.

My one gripe with the book - and it's a small one -was that I found the protagonist somewhat difficult to empathise with. Leigh, while being an interesting and well-developed character, felt strangely flat. Throughout the story, the only real emotions we see her engage with are those of curiosity and guilt. Her hunger for knowledge of the unknown and the unknowable pulls her forward, and repeatedly wins out over her guilt at the things she has to sacrifice. However, it's hard to find much depth in these sacrifices, since ultimately Leigh doesn't actually seem to want the connections and relationships she's giving up - instead, the source of the guilt is feeling that she should care more about them.

It'd be interesting to know if this characterisation was deliberate on the part of the author, or rather just not an area of focus in an otherwise extremely tightly-written novel. Unfortunately, I missed a Q&A with Martin MacInnes at my local bookshop, so I may never know.

I hope that it's fairly evident that I'd wholeheartedly recommend In Ascension. I think it appeals both to regular sci-fi readers, and to those who enjoy being drawn into a story where the veil of understanding is never fully lifted.


Having finished the book, I was left with loads of questions. I've collected some of these, stream-of-consciousness style, below. Spoilers for the whole novel follow.

  • What is the significance of the vent that the characters visit on the ship? Is it really deeper than anywhere else in the ocean? Why do the divers experience euphoria and a subsequent illness on entering the water? If it's the deepest part of the ocean yet discovered, why is it not further explored by the end of the book?
  • What is the alien artefact? Where does it appear from - I think this may be mentioned but I'd need to reread to check. Is the artefact related to the vent? Did it come from the vent? What do the concentric oval patterns mean? Perhaps the weirdest thing - how does it communicate with the dreams of scientists / engineers to pass on knowledge of the propulsion system?
  • Archaea and algae are big themes throughout. Why does the algae grow wildly after the acceleration of the spacecraft? What is the gene from the vent that is spliced into the algae?
  • Is it the acceleration of the spacecraft that messes with the bodies of Leigh and her other crew members? Is it some side-effect of the propulsion system? Or is it to do with leaving the heliosphere?
  • There's some ominous talk about the Great Filter being either space travel itself - travelling in interstellar space is impossible / destructive to a species - or what you find as a result of space travel. No conclusions here other than that humans' first attempt was unsuccessful, but it doesn't appear to have destroyed the species immediately.
  • It's heavily implied that the crew travel backwards in time before / while returning to Earth. Is this a consequence of leaving the heliosphere? Or is it something to do with the alien artefact?


While I really enjoyed the experience of reading In Ascension, I also think it's fun to speculate and discuss what everything meant - to attempt to make sense of some of the mysteries that linger at the end of the novel. With this in mind, I looked at some reviews to see if anyone had any good ideas for what was happening. Once again, spoilers.

The best clue I got for building my own understanding was from someone who referenced the description of salmon in the book. There's a focus on salmon returning to their spawning grounds, and their bodies disintegrating after they've laid their eggs to provide nutrients for their unborn children. This is a real phenomenon, although I'm not sure about the nutrient bit. This, along with the strong emphasis on cycles throughout the book, provides a possible explanation for events.

Leigh and her crewmates are participating in the 'life cycle' of life on Earth, although this life cycle takes place in a non-linear way through time. A lot of focus, early in the book, is put on the significance of the moment that archaea and bacteria combine to make eukaryotic life. The suggestion could be that the crew's return to Earth, with the rapidly flourishing algae taking over their ship and bodies, is the event that precipitates the creation of eukaryotes. In this cyclic version of events, the eventual evolution of humans and their travel to space is both the cause and the effect, with the journey acting as the completion of a loop. This lines up strongly with the scant evidence we have of what happens to the crew post 'The Event'. Their estimated "when", from looking at the stars, is 2 billion years ago, fitting with our knowledge of when eukaryotes first appear. The deterioration of the crew's bodies as the algae become more vital mirrors the salmon, reinforcing the idea of them as 'parents' bringing new life to Earth, their jobs done once the journey has taken place.

While this is a satisfying theory to me, it by no means explains everything in the story. The significance of the vent is still unclear, as is the role of the alien artefact. It serves as the catalyst for the journey by providing the propulsion system to humans, but is it also the mediator for the physical transformation that the crew undergo, or their travel through time on leaving the heliosphere?

One implication of the theory, at least for me, is that life on Earth is coming to a conclusion in the current time. This fits well with the backdrop of environmental degradation that the story is set against, as well as the increasing ill-effects that we see Helena and her children experiencing in the final chapters. In this reading, the mission can be seen as the final significant event of the planet in linear time, sowing the seeds for its own 'renewal'. Anything afterwards is a sort of post-script. It's not the case that humans immediately cease to exist, but more the sense that a tipping point has been reached from which there is no way back.

Do you have any interesting theories about the meaning of the book? If so, I'd love to hear them.