Infatuation must always fade. There comes a point when the initial thrill must either gently fade or deepen into love. Or catastrophically explode into a bitter falling out.

For me, The Knife Of Never Letting Go, the first volume of Patrick Ness's Chaos Walking trilogy, was pure infatuation. It was a novel I knew little about, which I had requested to review on a whim, and within pages I was smitten. The Ask And The Answer was a different proposition. There were now expectations. As a result I was able to look at the novel more closely, more critically than its predecessor, but still with a generosity of spirit. And this was repaid by a bold novel which took the original adventure in a much more radical and hard-nosed direction. At the same time, despite Ness's success in re-inventing his story, flaws did start to appear: an elevation of moral and political symbolism above what we might find believable; the dilution of the narrative voice; rather too much irksomely histrionic teenage angst; and a simplicity to its prose which sometimes veers into dumbing down.

Now the series concludes with Monsters of Men and those flaws haven't gone away. They are minor, but from time to time their repetition does provoke a disproportionate reaction, as though Ness has forgotten to put the towel on the radiator after he's used it just once too often. There is one particularly manufactured moral dilemma late on in the book that actually made me scream. More often, though, I am willing to overlook imperfections because of the obvious qualities the book is endowed with. Some I doubt I even see. I really think I am in love.

One of the problems I do see is the infatuation, as intense as ever, of protagonists Todd and Viola. As with The Ask And The Answer they spend and awful lot of time separated and shouting the other's name. When they aren't shouting, they are thinking about each other. Really, really intensely:

For her, I think, all my feeling behind it.

And I think her name—

Viola. (p. 8)

These are the last words of Todd's section; the first words of Viola's section are "Todd, I think". There is much more of this. Those excessive italics and that coyly truncating dash are also an unwanted stylistic trademark. You might put this down to the novel's audience but nowhere else does Ness display such deference to the tender years of much of his readership; for a series of such impressive thematic subtlety, the actual telling could stand to be similarly nuanced.

(But then I swing back the other way. Even as I'm writing this, I have to remind myself that I'm an adult and that Ness's ability to deliver such subtlety through such simplicity is an incredible boon in a children's novel. It does leave me wondering what an adult Patrick Ness SF novel would look like, though. Anyway . . .)

Todd and Viola's separation also makes the format of the opening slightly irritating. Monsters of Men jags rapidly between their perspectives, changing point of view every page or so. It is the literary equivalent of cross-cutting and just as easily overused. Whilst it might convey the excitement of a climax, at the beginning of a novel it seems gimmicky. However, if you can stomach it until page 77, it turns out there is a reason for it. In the first book we just had Todd's first person narration (and it was a huge part of the novel's charm), in the second book we had to adjust to Viola sharing the duties. So I should have guessed what would happen in the third book: Todd and Viola's voices are joined by a third viewpoint, that of 1017, the only survivor of the genocide instigated against the indentured alien Spackle in the last book (he is named after the brand inflicted upon him).

As I said, in hindsight an obvious choice but also very much the right choice. The Ask And The Answer ended—shockingly—with the re-appearance of the rest of the Spackle, apparently preparing to avenge the massacre of those enslaved by the human settlers. Todd's complicity in this crime and his subsequent guilt was the engine for much of the drama in that novel. Impressive though this depiction was, it does, of course, create a problem: the tragedy of a murdered indigenous people becomes the tragedy of the poor, hard done-by coloniser forced to kill them. As so often, those who are most in need of it are those who are denied a voice. Ness was obviously aware of this and has now remedied the situation.

This means that Monsters of Men is not the final show-down we might expect from another novel. It is true that we get a bit of the back and forth, cut and thrust, of the mechanics of warfare. However, no matter how much certain characters wish it, nothing meaningful can be decided by martial confrontation. As the much quoted full version of the title—"war makes monsters of men"—makes clear, there can be no winners. The novel, therefore, makes its story personal. In keeping with this, most of the clear political parallels from The Ask And The Answer are gone, although the odd one or two remain:

The Mayor ain't happy at all. "This isn't how we're meant to fight," he says, his voice low and sizzling. "Slinking around like cave rats. Night-time raids rather than open battle." (p. 191)

Similarly religion, which has been in the background of the two previous novels, is pretty much absent here, apart from one slightly odd off-hand reference from the Mayor which seems to cast Todd as Jesus:

"Even today, in what is arguably the greatest victory I've ever had, my first thought was, What will Todd think?" (p. 396)

Instead the ethical conflicts are more generic and more internalised. Even more so than the previous two volumes, this is a novel about soul searching. 1017 must face up to the implications of his hate and Todd and Viola must face up to the implications of their love:

If this is what Todd and I would do for each other, does that make it right?

Or does it make us dangerous? (p. 166)

Since this is the end of a trilogy we have to talk about closure. Both The Knife Of Never Letting Go and The Ask And The Answer end on huge cliffhangers, but that is not an option here. Endings are always hard but Ness does something very clever (and resonant) by bring the story full circle back to Todd's actions in the first book. It is one of the things that is so impressive about the novels that Ness does not forget and, just as crucially, he does not ignore. If you could distil the trilogy into a single message it would perhaps be this: actions have consequences.

After this, some will see the final chapter as a pulled punch, a sign that Ness has turned away from the unflinching view of humanity on display throughout the three novels. I prefer it to see it as a recognition of the ineffability of hope, a hope borne of the other constant throughout the trilogy: love.

Martin Lewis lives in East London. His reviews have appeared in venues including Vector, SF Site, and The New York Review of Science Fiction. He is the current reviews editor for Vector, and blogs at Everything Is Nice.