The game follows Lewton, the Disc's first and only Private Investigator. The game starts as Lewton is given a simple case to find a man. Since this is an Adventure Game set on the Discworld and acted out through a Film Noir genre filter, it soon becomes clear that there is far more going on.
- Badass Longcoat: Lewton. Brown trenchcoat with leather added over the shoulders, and a matching fedora.
- Connect the Deaths: Played straight.
- Conspiracy Theorist: Malaclypse, a servitor of Errata, Goddess of Confusion and Misunderstanding. This is a Shout-Out to out world Malaclypse the Younger (a penname for Gregory Hill), the supposed creator of Principia Discordia, which details the worship of Eris, the Goddess of Chaos.
- A reasonable chunk of his gibberish is actually true, and covers a lot of Discworld (and Discordian) mythology/history.
- Cursed with Awesome: Discussed. Lewton isn't very happy about becoming a werewolf, but Carlotta (who infected him) says it's a great gift. It does turn out to be pretty useful.
- Darker and Edgier: The entire game feels like a dark Watch book, to fit with the Noir theme. It is also quite darker than the two previous Discworld games, both in feel and in colour palette. Actually works.
- Deadpan Snarker: Lewton, and oh-so-many others.
- The Dog Was the Mastermind: Well, more accurately the bestial serial killer is the god Anu Anu who spends most of his time in the form of a small dog. However, it is his worshippers who choose his victims, and they are all in turn being manipulated by the real mastermind.
- Editorial Synaesthesia: Werewolf vision.
- Eldritch Abomination: Nylonathotep.
- Evil Sounds Deep: Horst. Really bizarrely, when you realize he's one of several characters voiced by Robert "Kryten" Llwellyn.
- Expy: Many of the characters in the game are quite clearly Discworld versions of characters from Casablanca and The Maltese Falcon. "Tomb evacuator" Laredo Cronk is an obvious Lara Croft reference, and the Indiana Jones theme occasionally almost plays in the background of the archaeologist's guild.
- Femme Fatale: Carlotta.
- Film Noir: Oh so very much.
- Friendly Neighborhood Vampire: The vampire pianist Samael, probably a black ribbon.
- Friend on the Force: Playing the role of Detective Tom Polhaus is Corporal Nobby Nobbs. So no help there.
- Genre Savvy : Some of the villains, not that it surprises anyone.
- Genre Shift: For the most of the game, the game seems like an Affectionate Parody of Film Noir in general, and Casablanca in particular. Then towards the end, it suddenly turns out to be a Cosmic Horror Story, with Noir elements.
- Half-Human Hybrid: The bartender Mankin is half-elf, in the Discworld setting, that makes him very unpopular (since Elves are cruel and vain beings from a parallel dimension), and gives him no special powers. He is a very bitter person.
- Hostage for Macguffin: Played straight, Horst holds Ilsa for the Golden Sword.
- How We Got Here: The game opens with a cinematic in which the protagonist is chased down and stabbed to death. You spend the first half of the game looking for the McGuffin whose possession will result in your untimely demise.
- I Know You Know I Know: Lewton tries to do this on Malaclypse... it works, after a fashion.
- Large Ham: In-game actor Privetier is a huge ham, much to Lewton's displeasure.
- Let's Play: A video playthrough by TheRussianGestapo on YouTube.
- Noir Episode
- Only Smart People May Pass: It looks like the game is headed for this when an ancient guardian wants to ask you a riddle to see if you are worthy to receive the McGuffin. Then come the subversions, first by the guardian who happened to forget the riddle during his 400-year-wait (but still insists to only hand the item to those who answer it) and then by Lewton who points out that someone of the unworthy faction would just hack the weaponless guardian to pieces. As he's in somewhat of a hurry, he gives the guardian the option to hand over the McGuffin... or he'll just pretend to be unworthy enough...
- The guardian relents.
- Out of Character: Insofar as characters who appear in the books are hanging about, they're reasonably true to the books... except for Vimes. Vimes holds a massive grudge against Lewton because the particular indiscretion for which Lewton was fired (accepting a bribe) ranks just short of murder in Vimes' book (which is true to the books), and he's only too willing to accept that being found unconscious at the crime scene is proof of guilt. This in contrast with his portrayal in the books where he hates "clues" (like, say, being found unconscious at the crime scene) because they often create fantastic stories out of the theories but do little to solve the case. In the books, his first duty is to justice, and if that means letting the guy he doesn't like walk so that the real culprit ends up behind bars, he doesn't want it any other way.
- Essentially, Vimes has been handed the role of Sam Spade's nemesis Lt. Dundy even though it's not a great fit because it's still much closer than giving it to, say, Carrot.
- Parody Name: Mundy for Thursby; Jasper Horst for Casper Gutman; "Mount" Malachite for "Moose" Malloy; Nylonathotep the Laddering Horror for Nylarthotep the Crawling Chaos.
- Posthumous Narration: Lewton gets killed in the opening cinematic, and and a good chunk of the game is a flashback.
Lewton: I've had some bad days since I started work as a private investigator. But I've never woken up dead before.
- Private Detective: Lewton both embodies and parodies this trope, due to the Disc's Theory of Narrative Causality: he doesn't know why being a private investigator means he has to wear a trenchcoat and fedora, but he's quite sure it does.
Lewton: A lot of strange things had happened to me since becoming a private investigator, but the weirdest was the irrepressible sensation that the most important thing for me to own as a P.I. was a door, with my name painted on the glass. Some mysteries are best left unsolved, I guess.
- Private Eye Monologue: Played straight and parodied, with the usual Discworld insistence that metaphors have to be precise. Also, Lewton is a very, very bitter man.
- Shout-Out: The game has innumerable shoutouts to Casablanca, and popular culture in general.
- Smite Me Oh Mighty Smiter: The death of Mooncalf.
- Take That: The Lara Croft Expy basically serves as a vehicle for the writers to tear into the Tomb Raider franchise.
- Theme Serial Killer: There was a parody of Theatre of Blood, with the plays of Hwel, the Disc's version of Shakespeare.
- Trojan Horse: Used by Lewton to board the Milka, and by a killer to enter the Patrician's Palace.
- Wham! Episode: More like wham scene: the library scene when you finally figure out that the game is a Cosmic Horror Story.
- And later still, when Lewton finally pieces some things together:
Lewton: At that moment I realized what was odd about the bone. It had been a human femur.
- Whole-Plot Reference: To The Maltese Falcon, Farewell My Lovely and The Big Sleep. All happening at the same time, and with one character playing the roles of all three Femme Fatales.