I liked this one more than the second one, though I did miss Hugo. I agree with most of the negative reviews that macguffins abound and the ending was much too tidy, but there's just something about the writing and the world and the characters that makes me really not care about that. I love Berenice, I love watching her spectacular fuck-ups. I liked seeing things from Anastasia's perspective. I definitely have some biological bias because all the descriptions in this series of human beings with pineal glass implanted in their brains, with their free will stripped away and the pain of geasa on their faces, really made me feel sick. Even knowing that the clakkers have consciousness, are people, I couldn't muster the same sort of empathy for them. Hopefully our future robot overlords will forgive my fleshy brain for such things. ( )

This whole series has felt so timely in light of advances in AI and in our on-going problems with exploitation around the world. In this final chapter, the Clakkers have achieved independence of a sort - but they are in a battle with Queen Mab who would replace one kind of slavery with another. Anastasia and Beatrice also both have to face their part in the collapse of their world and put their great intelligence to work to save some place for humanity in the new world that they have unleashed. This series has been rare in its ability to deliver a truly entertaining story and at the same time invoke essential thought provoking questions. ( )

[This review provides minor spoilers, but more to do with the writing structure of the ending than its content. I do not reveal the fates of any characters.]

I feel like I'm trembling under the strain of a deep-rooted geasa. I loved the first two instalments in this trilogy and, for reasons of gratitude and uniformity (the other two have a five-star rating from me and are on my Favourites list), I dearly want to be able to say that The Liberation, the third and final instalment in author Ian Tregillis' Alchemy Wars, is a fantastic end to the journey. But I have to resist that inner compulsion and say honestly – but very reluctantly – that I found it rather underwhelming.

This is not to say it is bad – not at all. The writing and world-building are as immaculate as ever, and the series remains a page-turner that allows you to read through at a rate that belies the page count. Tregillis remains one of the finest contemporary writers of speculative fiction and one who can balance his heady ideas with storytelling entertainment. Truly, there's no major error in The Liberation that you could seize on to bash it over the head with. (The closest Tregillis comes to an actual mis-step here is that Longchamp and Montmorency, whose 'deaths' in the previous book were respectively tragic and delicious, prove not to be dead after all, even though they serve no real further role in the story.) Rather, I read the book with a growing sense of disquiet. It's just not as good as the previous two, and it doesn't evade the pitfalls that arise to try and thwart any final instalment to an ambitious 'blockbuster' work.

The most obvious and important of these pitfalls is the need to reach an endgame. In any expansive plot the storyteller has to eventually bring all the threads together and provide resolution. It's a daunting task, and unfortunately Tregillis relies on the old cop-out: Have all the main characters converge on a single location, and have them fight it out. Not only have we had our fill of spectacle in the Alchemy Wars trilogy with the siege of Marseilles-in-the-West in book two, which did it much better and with more attention, but to resolve plot threads in this fashion requires liberal application of deus ex machina strategies. So Tregillis does, to little real satisfaction or thrill.

It also means we have to pay greater attention to characters who are important to plot resolution but aren't necessarily interesting or likeable. In The Liberation, we are compelled to spend a great deal of time with Anastasia Bell, the ruthless head of the Clockmakers' secret police, who finds herself on the frontline as the Dutch Empire faces the vengeance of the freed mechanicals. Due to the demands of the plot we are encouraged to root for her to an uncomfortable extent – this, the Dutch regime's equivalent of Himmler or Heydrich, who has had a hands-on role in human experimentation and torture (most notably, on poor Pastor Visser). Her prominence was a major contributor to my growing unease; indeed, most of the novel is just a tennis match of point-of-view chapters between Bell (or 'Anastasia', as our growing familiarity forces us to refer to her as) and her French counterpart Berenice (her of the clunky, affected potty mouth).

The rush to the finish line can be identified as the main reason behind The Liberation's inferiority to its predecessors. To get there quickly and still meet the demands of the plot, it has to shed a lot of weight. Unfortunately, it does not streamline – rather, jettison. The psychological angst of book one and the desperate uncertainty of book two have been replaced by bombast and single-minded malice. The fascinating and labyrinthine theme of Free Will has been replaced with a crude religious angle in which Daniel (formerly Jax) has become a Brasswork Jesus. The catharsis of liberation is rarely experienced amidst all the bloodshed, and comeuppance manifests itself only in rather petty engineered moments, such as when a fleeing Anastasia Bell and her cronies wade through a sewer of shit. Some interesting questions, such as the origins of Queen Mab, are never answered. New ones raised by the blink-and-you'll-miss-it revelation that Adam (from the first book – remember 'Clockmakers lie') was deliberately created as a rogue to cow the Dutch populace (pp38, 217) are again never exploited: the ramifications of the Adam gambit are never acknowledged. It's treated as little more than a curio – an Easter Egg for attentive readers.

The dismantling of previous strengths of the books also exposes other previously hidden flaws to the elements. I have been led to an unwelcome late realization that the characters aren't as interesting as I had thought. Jax evoked sympathy in previous books as he was the vehicle through which the mechanicals' suffering and yearning for freedom was communicated to us, but he lacks direction as the benevolent and gentle Daniel. His reluctant messiah arc is not fleshed out; had it been so it might have redeemed the switch away from psychological dilemmas to soulful religiosity. I reluctantly realized I didn't care as much about the fates of Berenice or Daniel – or, indeed, humankind(!) – as much as I should by this point in the story.

The trilogy has been a fine one and at times – especially in the previous two books, The Mechanical and The Rising – it has been exceptional. The third retains some qualities of its predecessors, particularly in its readability, but whilst The Liberation provides a tidy end it is not a great one. The Alchemy Wars have essentially been a cautionary tale about mortal hubris and a discussion about the nature of free will, but these themes are never given the capstone that they seemed to be building towards. This is a shame, because such themes are in vogue (most notably in the HBO TV series Westworld, which wisely deals with them more enigmatically, and on a slow burn). The closest Tregillis gets to real insight on these matters comes on pages 115-16, when we are presented with the prospect of a schism between benevolent and vengeful mechanicals:

"That gave Berenice pause… The last thing she wanted was to get involved in the mechanicals' first internecine conflict. God stepped aside when His creations warred with one another… Perhaps the true price of freedom – or the mark of it – was the utter indifference of one's maker."

The passage deserves quoting as it reminds us of Tregillis' quality and the potential of the story, even if it did remain (just) unfulfilled. The book could have done with more such introspection and manoeuvre, and less bombast. The series has been a concept that required a dark ending, cloaked in ambiguity and flavoured by a grey morality, but it didn't get one. Rather, we got a human and a mechanical holding hands – seriously – and a conventional Hollywood heroic sacrifice.

The most instructive part of The Liberation is, surprisingly, its Acknowledgements page. Here, Tregillis thanks those who encouraged him at those times when he "couldn't bear the thought of spending yet another evening at the keyboard" (pg. 436). I'm always wary when writers stress just how hard it was to eke out a story. Now, writing is of course very hard, and conceptualizing and writing a story is especially brutal. It's like having kidney stones: it has built up unhealthily inside of you and it wants to get out but it Just. Won't. Leave. But when a writer feels that weight so heavily that they are compelled to stress just how hard those nights in front of the keyboard were this time around, it provides an insight into the storytelling decisions. You have to write – not because you want to do it, but because you have to finish it, you have to wring the last drops of water out of a rapidly-drying cloth. It provides a possible explanation for Tregillis' understandable reliances on deus ex machina, route-one plotting and the keening rush to the finish. I sympathize, but it is certainly ironic that a novel and a series about this subject matter should have the tone of its ending decided by a sense of compulsion. ( )