Leviathan Falls (The Expanse #9) by James S.A. Corey – Series Finale

Format: Paperback
Read: March 2026

I finally finished The Expanse! I started this series in 2017, so 9 years ago, and it took a re-read of 6 of the books to get it done. This might be the longest series I’ve ever read to the end of, except for The Famous Five. I read all 21 of those as a child! And since this is a series finale, my thoughts are reflective on the series as a whole, and there will be unavoidable spoilers for the earlier books.

I am not typically much of a series reader, so the fact that I was motivated to read all 9 of these books speaks highly of how engaging it is! But… as you may glean from the 3-star rating, I did find this last book disappointing. In fact, I gave the last 4 books only 3 stars. Honestly, everything after Nemesis Games (book 5) has been missing something for me.

It is often said that this 9-book series can be read as a trilogy of trilogies. The first part is humanity discovering the protomolecule and the ring gate technology, the second is humanity expanding colonies through the ring gates which has a lot of political consqeuences, and the third part is the rise and fall of the Laconians and an eleventh hour return to the original thread of the mysterious Big Bad Aliens that ended the civilisation that built all the fancy technology (aka, the Whitewalkers of The Expanse if we were to think in a Game of Thrones/ASOIAF terms).

For me, I think what I most enjoyed about this series was the strong character development, the human villains and the intriguing mystery of the builders and the Big Bag threat. Sadly, those are the elements that fell away in the final of the series.

The thirty-year time jump in Persepolis Rising really confused how I saw the characters, and it also meant that the authors dispensed with any meaningful character growth for the main Roci crew. They’re now in the 60s and have been together for decades, how much more could they and their relationships change? The Laconian Empire plot also went nowhere in particular, and for me failed to make any point about military dictatorships. Duarte’s return in Persepolis Rising ended the last bit of intrigue in the series, and the Laconians were just too big and powerful. They were unbeatable, and that took all the wind out of the sails in books 6-7, and it never came back for me.

Most disappointing is that there was never any real resolution to the overarching background threat of these mysterious aliens. We never come into contact with them aside from bizarre space events. It ended up being in a human squabble that was resolved, of course, by Holden. Actually, the ending really reminded me of Mass Effect 3 – it’s nowhere near as disappointing as that, just plot-wise we are in the same realm! – one lone human (James Holden) decides the fate for everybody else, and it is a choice between keeping the fancy technology but losing all human individuality (think Pluribus, we’re doing hive minds, this is akin to the green ending of ME!) or lose all the fancy technology and the ring gates (aka the Mass Effect relays!) but get to stay as individual humans (basically the red ending). I love Mass Effect with all my heart; it is a part of me, but I never want to be reminded of those last 15 minutes of it, and also, this was just a derivative and uninteresting way to end The Expanse.

I will confess that I was quite bored by the last half of this book, and by the end, I’d basically mentally checked out (it’s why it took a month to finish!). I was no longer invested in any of the characters because they were all just shadows of their former selves (and I’m not even going to get into what was going on with Amos), and so I was unaffected by what I’m sure was intended to be emotional farewells for everyone.

This is disappointing because this series had some serious highs! The first 3 books are truly excellent, and Nemesis Games has some of the most gripping and shocking events I’ve read in a book, as well as some really great and interesting character development for Naomi! There are some fantastic, memorable characters, especially my favourites Detective Miller (who was only really in book 1!), Amos Burton, Chrisjen Avasarala and Bobbi Draper. Even James Holden is memorable in his own way.

If I ever decide to re-read the series, I would only go as far as Nemesis Games (book 5) and leave it there. Unfortunately, I found nothing to really recommend about the following 4, now knowing how it ends. It also makes the cancellation of the Amazon Prime adaptation make a bit more sense to me – I am now looking forward to rewatching that and finishing it.

I would still really recommend the series because, as disappointing as I found the ending, it was not a bad ending… it was just fine. I’ve definitely come across much worse. Also, none of the books dipped below 3 for me. I still found things I enjoyed about the characters and the world, even when the plot went in a direction that didn’t resonate with me.

For the law of fives bingo, this counts for the last book in a series, Locus award winner, over 500 pages, Sci-fi genre explore (Space Opera), and Muskoka is a dog analogue from Laconia, so I’ll count him as an animal, and then there is what Amos ends up as as a fantastic creature.