Halo: Last Light is a novel set in the Halo universe which follows the adventures of Master Chief, Cortana, and a variety of military heroes as they struggle to defend humanity from the villainous Covenant. Halo: Last Light is set after the human-Covenant War when the super-soldier SPARTANS are being deployed in less-epic roles as support for the regular military. It's also a time when peace is being made with the various former Covenant forces and the biggest threat to humanity is from potential separatist groups.
This book opens up on the planet Gao, which is a former Insurrectionist planet bubbling with resentment against the UNSC. The UNSC has discovered a Forerunner ruin which contains an ancient A.I that could conceivably unveil all of said race's secrets. Sending a battalion to occupy the cave system, they start hunting the A.I. despite its veritable army of Sentinels and other defenses. Unfortunately, the A.I. is clever enough to start murdering local Gao citizens and frame the UNSC for it. This brings Inspector Veta Lopis to investigate and casts suspicions on the transhuman Spartans assigned to the unit.
The book is a non-mystery as we find out the A.I, known as Intrepid Eye, is responsible for the murders in the second chapter but our protagonists aren't clued in until much later. This is an interesting way of handling the story even if I think it might have been better to leave it an open-question until the end. Certainly, there's enough going on with plots and counter-plots that this could have been a storyline which held our attention indefinitely.
The characters are, surprisingly, some of the best in the Halo franchise. I love Veta Lopis as a character and think she's a great heroine we haven't seen before in the franchise. A determined detective, she is unsympathetic to the UNSC but uninterested in politics. Her interest is purely in catching a killer and she refuses to let issues like military concerns or classified data interfere with her investigation. The fact this attitude gets her in a lot of trouble and screws with the mission is part of the book's fun.
The character of Fred-104 is also a great Master Chief substitute. As one of the few surviving Spartan-IIs, he's refreshingly angst-free and as devoted to the UNSC as one of the Spartans should be. The fact he's set up a fatherly relationship with the Spartan-IIIs is appropriate as well and how I imagine such an interaction would go. The Spartan-IIIs also get a lot of development with Gamma Squadron's "berserker" modifications getting special attention as we see the downside to their transformation.
I liked the flirtatious relationship between Inspector Lopis and Fred, especially as it doesn't really impact their contradictory professional goals. Neither of them is willing to compromise their missions despite coming to like and respect the other. I also liked the world-building we got for the planet Gao, which is our first real look at what it's like to be on a human planet in the setting. I also like the fact Troy Denning chose to make it South American feeling versus going for another America-themed colony.
The politics of the setting proves to be more interesting to me than the non-mystery and I've got to say I like how Troy Denning expands on the conflict between the Insurrectionists, the UNSC, the former Covenant forces, and everyone caught in-between. Halo villains tend to ward the grandiose and comic-booky so having ones who are relatively sympathetic with understandable motivations is a nice change of pace. Slimy Gao politician Arlo Castille is hardly sympathetic but realistic in a way which doesn't require any mental hoops to justify.
There's a lot of good moments spread throughout the book like Inspector Lopis discovering the Spartans-IIIs are adolescents, the Spartan-IIIs closing ranks when they think Inspector Lopis believes one of them is the serial killer, the clandestine meetings between the Covenant and Insurrectionists, plus the perspective chapters of Jiralhanae chieftain Castor who is perhaps the first Brute which can be called admirable in the history of Halo. Is Castor the antagonist? Yes. Castor is also a far more honorable opponent than Arno Castille or the Spartan's own superiors.
The use of a resort built into a set of natural springs and caverns is a unique location to set a military science-fiction novel and I have to give props to Troy Denning for this. It's a place of luxury, military operations, and natural beauty all in one. Much like the in-universe Halos themselves, they combine the constructed with the organic in a way which is both entrancing as well as threatening. Most authors miss this quality in their books so even though they're set in the same universe, they don't have quite the same "Halo feel" as players did wandering around the gorgeous plant-covered ruins in the first three games.
My biggest problem with the book is the dual Maguffin/antagonist, Intrepid Eye, who is a lot less developed than the other antagonists. With ruthless but understandable ones like Arno Castor and Castille, it's annoying to have a self-deluded psychopath like Intrepid Eye get so much attention. No matter what the evidence presented to her, she maintains the Forerunners are still around and humanity is a disgusting race of vermin fit only for extermination. It's a bad day for an A.I. when you're wishing for a rampant Guilty Spark to take their place. Despite this, Intrepid Eye is not enough for me to lower my score for the book.
In conclusion, I heartily recommend Last Light and think it's probably one of my favorite Halo novels. The fact it's a relatively low-stakes and character-driven piece makes this a stronger work, IMHO, and I would recommend it for not only fans of the franchise but also individuals who just happen to love science-fiction.