Halo: Last Light is a 2015 novel by Troy Denning set in the Halo series, which follows the Spartan squads Blue Team and Team Saber on a mission to a distant colony.
It is July 2553, four months after the end of the devastating Human-Covenant War. Now lacking a common enemy, the United Nations Space Command and colonies sympathetic to the Insurrection have started to grow hostile to each other again. These tensions flare on the independent colony of Gao, where mysterious murders have been occurring in its Montero Caves shortly before the UNSC sends its forces, including a team of Spartans, to lock down the site. Demanding their own investigation, Gao's government sends special inspector Veta Lopis to solve the murders, though the UNSC insist that the Spartans "supervise" her. But the Spartans have their own mission, and Veta suspects they may have had the means to carry out these crimes...
It is followed by a sequel, Halo: Retribution.
Halo: Last Light contains examples of:
- Adaptational Badass: Four Sentinel drones are a heavy challenge for four Spartans, being armed with particle lasers and durable energy shields. In the games... just spray them a while with an automatic weapon and they'll shatter. Considering that Halo 2 had already established that there are multiple types of even just basic Aggressor Sentinels, it's possible the ones in Last Light just happen to be a particularly tough variant, akin to the Onyx Sentinels from Halo: Ghosts of Onyx.
- A.I. Is a Crapshoot: Like most other Forerunner AIs, Intrepid Eye has become sanity-deficient thanks to millennia alone in her facility. With her, it manifests in a sociopathy towards humans, contempt for lesser constructs like Engineers or human AIs, and a refusal to believe that the Forerunners are extinct like all the records she finds tell her.
- And I Must Scream: Not played for horror, but twice Fred ends up locked inside inert armor without any way to move it. The first time he survives a crash landing and the armor locks to save him, and the second its battery is destroyed so Intrepid can't take control of it.
- Banana Republic: Gao rather clearly takes after this imagery with its rebellious past, tropical environment and Hispanic Theme Naming.
- Belligerent Sexual Tension: Fred and Veta's arguments became unusually charged throughout the story. See Ship Tease.
- Child Soldiers: Veta comes to find that the S-IIIs are still in their teens. While she's horrified that the UNSC would subject them to such experiments, the IIIs themselves are so used to being supersoldiers that they think she's overreacting.
- Cruel and Unusual Death: Most of the victims are found in a mangled state, with limbs ripped off, throats pierced, and skulls crushed or having had stuff shoved inside of them.
- Dark and Troubled Past: Veta was abused and held hostage as a teenager, and had to escape by killing her captor. Now an adult detective, her past looms over her via her zeal for catching criminals and her fears of tight spaces and attachment.
- Elite Mooks: The battle-jumpers, armored stealth troops who are basically Gao's version of ODSTs. However, they prove to be absolutely no match for the Spartans, even with the advantage of air support.
- Fantastic Noir: No "saving the galaxy" plot, just a crime mystery set in the 26th century.
- Historical Hero Upgrade / Historical Villain Upgrade: In-universe. Intrepid Eye dismisses AI Wendell's accounts of the Flood-Forerunner War as Lifeworker propaganda. As she was constructed by Builders, Intrepid views the Lifeworkers as obsessed eccentrics and the Builders as the geniuses whose measures like the Jat-Krula Line and Halos were for the greater good of the galaxy, even though much of what Wendell is quoting is from The Forerunner Saga, which showed the Builders to be xenophobic tyrants and the Jat-Krula to be outdated and ineffective, while the Lifeworkers were the most moral caste.
- Karma Houdini: Discussed. Intrepid Eye is captured by ONI at the end of the novel. Veta protests that it should be destroyed for its numerous homicides, but Kelly replies that it's just a malfunctioning machine doing what it was told to and so "punishment" doesn't apply to it. Veta still thinks they're wrong, since Intrepid was pretty deliberate about her murders, but realizes the Spartans are more acquainted with killing on orders than she'd ever understand.
- Out of Focus: Spartans Kelly, Linda, Tom, and Lucy only appear sparsely, while the main focus is on Spartans Fred, Ash, Mark, and Olivia along with detective Veta.
- People Puppets: Of a more technological sort. Intrepid's last gamble to hijack Fred's armor to try to kill Veta. Intrepid nearly overpowers Fred, but Veta saves herself by destroying Fred's power supply unit, rendering the armor inert.
- People's Republic of Tyranny: Gao is implied to become one after Arlo Casille has himself instated as the de facto dictator of the planet.
- Psycho Serum: Veta eventually discovers what makes Gamma Company Spartan-IIIs unique from other Spartans: they've been injected with unique "cocktail" drugs that make them more persistent and aggressive under injury or stress. While Halo: Ghosts of Onyx showed them to have the issue of altering their brains so much that Forerunner A.I.s couldn't recognize them as human, Last Light explores their other side-effect: if they go for more than a day and a half without taking their "Smoother" drugs, they risk going on rampage.
- Reading Lips: It turns out Veta has picked up a few tricks from a deaf friend of hers and is able to pick up parts of the conversation between Fred and his superior, including words like "Forerunner" and "ancilla".
- Reverse Whodunnit: Intrepid Eye is revealed as the murderer from the second chapter, and Fred and ONI know it. The conflict instead comes from how long they're going to insist on keeping it secret from Veta per ONI's orders, and how which innocents Veta might mistakenly charge if not told the true killer, not to mention Intrepid herself running amok.
- The Social Darwinist: Intrepid Eye eventually accepts her new mission is to serve humans, but it doesn't slow her murderous tendencies in the slightest. Instead she decides that these "barbarians" aren't worthy of the Mantle yet and her actions are "pruning" them to become a nobler species.
- Ship Tease: Despite being on opposite sides and frequently arguing, Fred and Veta develop an unusual kinship.
- Fred notes that Veta looks, to him, more like a model than a Hardboiled Detective.
- Half their conversations result in Fred trying to conceal classified information and Veta trying to trick it out of him.
- Both get a chance to admire each other's bodies. While crawling through a dark tunnel, Fred annoyedly notes that the most he can see is Veta's butt blocking the view ahead. Later on Veta sees him changing out of malfunctioning armor on the field, and thinks she might've found his superhuman muscles a nice view if not that they are currently on the run for their lives.
- An incident also occurs where Fred's armor locks up and he has no better way down the hill than falling over and sledding down. Veta hitches a ride on him, and he recalls finding it really exciting, joking to her afterward that next time he gets to be on top.
- Team Mom: After Veta gets really concerned with the Gammas' safety due to their accumulating injuries, the S-IIIs start jokingly calling her "Mom". Veta hates it at first but eventually stops caring what they call her as long as she gets to support them.
- The War of Earthly Aggression: Before the Covenant War, Gao supported the Insurrection. Three decades later their old rivalries are started to reemerge, and some of them would go as far as to ally with a splinter faction of the Covenant to fight what looks to them like UNSC occupation.
- Worthy Opponent: After attempting to kill Veta three times and failing, Intrepid Eye starts to view her as one of those branches of humanity that may be worth keeping.
- Why Did It Have to Be Snakes?: Due to an incident in her teens where an abuser locked Veta in a tiny cellar for three weeks, she's since had a fear of tight spaces. As such, this cave mission is not high on her favorites, though she refuses to be coddled and insists on crawling through anyway. While her phobia never gets further than momentary hesitation, just a few seconds of reluctance are enough for the Spartans to notice and to cause her trouble when she tries to escape from an airlock Intrepid Eye locks her in.
- You Can't Go Home Again: Thanks to aiding the Spartans and become a target of her ex-employers-turned-Innie, Veta can't ever return to Gao at the end of the story. However, Admiral Osman offers her a chance to keep up her detective work as a "Ferret" working for ONI alongside the Spartan-IIIs.
