"Oh aye, Rattus Faber are cunning little mechanics. Tiny hands, tiny details. Nibble's a good sort. Grumpy, but proud of his work."

"I'll... take your word for it. Ravnica's rats tend more toward large, angry, and destructive, with optional swarming. And, hrmm."

She turns to the thrulls, "Bephel, wait at the door. Elpheb, hang two feet back from me and don't approach the rat unless he attacks me."

"Right," she says, turning back to her helpful guide, "After you."

The officer shrugs and heads in. Inside, in contrast to the dilapidated exterior, everything looks sturdy and well-maintained. The guns, accessories, and ammunition are neatly laid out in padded glass cases, with small labels. There's also a sign that says 'Shoplifting? This is a gun store.' With a target reticle over a hunched figure carrying a bag.

"Nibbles! I've got a customer for you." The officer calls out.

An overall-wearing grey-furred rat leaps down from an overhead walkway, scurries across a shelf and tiny bridge, and up to the counter in a handful of seconds.

"Grits, if that thing stops another customer from coming in, shoot it!" Is the squeakily shouted reply. 

A ratty face wearing an aviator cap peeks its head out from a hidden slat just long enough to be obvious, then shuts it with a slam.

"Your friend doesn't look very happy to be here, Mox," the rat-owner says.

"I'm not the Ambiguous Officer anymore?"

"You'll always be Mox to me. Why should I sell to her, eh?"

"Because money. And being one of the first to witness the new gossip."

"Point. Welcome to my store, miss. You can go wrong with ratwork, but only by hiring the wrong rat."

"It's not that I'm unhappy to be here, it's that I'm very foreign and intelligent rats are the second most surprising thing I've encountered so far. Our rats had enough size and ferocity to win fights with my thrulls, and enough viciousness and stupidity to start those fights. Please don't shoot them, they're slow to replace and won't act out unless I tell them to."

"Grits, amend that. Regular rules."

Tap-tap from inside the wall.

"Right, well I promise we can provide you the equipment to ruin your foes' day quite thoroughly. What kind of weapon are you in for today, Lady...?"

"Karlov, or the Dire Lady. Very foreignness comes with not being trained with guns at all, so I was suggested a shotgun."

The rat sighs.

"Probably want it low-maintenance too."

He sighs again. "Well, I can do shotguns, I can do low-maintenance and smokeless powder and safe as Port Avon, but this is really seeming more and more like a waste of my art on someone who won't be able to properly appreciate it."

"If I've made a mistake bringing her here we'll get out of your hair..."

"Very foreignness, hmm? I don't suppose you have some interesting engineering tidbits or exotic weapons that I can puzzle over, that'd be fascinating. No Rattus Faber? Who maintains the wiring and the piping? Who gets inside engines to oil and clean?"

"We have a lot fewer of them, I'm afraid; most things run on magic, which is much better-behaved than the kind you get here. I think sprites and fairies - humanoid but about your size - do some maintenance on them, but mostly for precision pieces. The rest is made to be serviced from the outside, and Izzet goblins handle it. They're about yea high," she holds her hand at about stomach level, "and have green scaly skin. The Izzet are the guild of mad scientists - they make their dull ones handle the infrastructure for the rest of the people. Which we're all thankful for, because if they let the clever ones do it, it'd work ten times as well but explode once a month."

"That's the reputation ratwork has, but it's a damned stupid one because it's the socioeconomic system that oppressed rats and made us all desperate to survive. Sure, hire a rat to fix your boat and they'll do it for a tin of biscuits but it might fail suddenly later. We fixed it with gum and string because that's all we have, because people were literally hunting us. C'mon, give me something, some colorful Izzet thing that you have half a clue how it works?"

"Hmm, closest thing to guns we have are 'bam-sticks', which look pretty much like the barrels of these. Two-part charge, enhanced by red mana - if I work out how to teach anyone to use it, I'll come to you first - but basically alchemical, they either burn mercury and cyanide in precise conditions - hmm, that might need magic, actually - or dissolve mercury in... acid of ammonia, I think it's called, and some simple alcohol. Or if you like alloy-forging I know something about mizzium, which is the toughest metal known."

"Acid of ammonia and alcohol... Would that make an ester? No, no. Mmh. Oh, wait. That's just mercury fulminate, isn't it. White powder? Explodes if you jostle it too much? That discovery was the key to modern mostly-reliable impact fuses, you know. Good stuff, good to know the chemistry's the same at any rate, means mizzium might be promising."

"Sounds about right. When I've seen it, it was a mixture of red and blue, but they'd add color if they could, red and blue are their guild colors and they're as egotistical as anyone. Mizzium cannot be bent, and can withstand the highest heats ever recorded and any amount of fire-enhancing magic. I can write down my estimates of the ingredients and proportions, they're economically important, but the final synthesis is secret. They say it requires dragonfire, but they basically worship their leader, Niv-Mizzet, who's the last dragon alive, so if anyone claimed to have another way, they'd probably be executed. Possibly by being thrown into the mizzium synthesis. You need incredibly high temperatures, certainly, I don't know your scale but it's at least, oh, fifty times the difference between ice and steam?"

He laughs and rubs his hands together. "Cannot be bent or cannot be bent without shattering first instead? Now that's an exciting sounding synthesis. What do you say to a free gun for everything you can think up about it and an explanation of what red and blue mean? Yes," he says impatiently to the officer. "It still counts as a referral. And you can listen in."

"Hmm, it may shatter under extreme pressures, I'm not sure. They salvage it from their wrecks and they're very proprietary about that - they revere the substance somewhat, like the dragon who makes it, hence the name. But it's tough enough for thin spars to support twenty-story towers for decades without maintenance, maybe centuries. Red and blue - so, as far as theorists know on Ravnica, magic is fundamentally composed of five types, usually called colors. Each of the nine guilds is aligned to a different pair - mine is white and black, as you might have guessed from my clothes. Red is passion, fire, intuition, anarchy. Blue is ice, wind, technology, minds. Izzet combine the two and get geniuses who make massive leaps of logic and are usually right, but when they're not, it misfires. And sometimes levels whole city blocks."

"That does not sound like any remotely mundane material, no no. Hmm. I can't say the colors make sense to me, I'm a rat of hard science."

"Heh. Sir, blue mana would stick to your fur. Science, the progress toward understanding and control of the fundamental forces of the world, is just about the bluest endeavor possible."

"And since I'm a cantankerous and proud bastard of a rat too, maybe I'd fit right in with them, eh?"

"It would depend a bit on how you feel about big explosions, but yes, you'd probably be a shoo-in. Are most rattus faber craftsmen - craftsrats? - like yourselves?"

"Positively, if I'm behind a nice sturdy blast shield. Yes, by long tradition and natural, possibly even designed, inclination. Tinkers, mechanics, tailors, gunsmiths, welders, machinists, canners, chemists, pneumaticists, electricians, and more. Several of my relations are soldier types instead, that'll be second most common, and my granddaughter Filo she became a ratronaut, but even that involves maintaining her rocket between scouting missions!"

"You sound like Izzet, only much more sensible. And unlikely to... actually, I think listing all the stupid callous things Izzet do and you don't would just seem offensive. I'll just summarize it as 'designated close-range explosion observer' is, as far I can tell, a common hereditary job title for Izzet goblins, and it's as bad as it sounds."

"Yes, well, let's move on. Untrained shooter, hmm?"

"Yeah. I've used a bam-stick, but not often and I'm an awful shot. Though I've also never had the need to defend myself personally, and the Ambiguous Officer suggested they'll try and give me a proper shooting lesson; maybe I'll be competent with a little practice now that I'm motivated."

"So no marksmanship rifle for you..."

"I was thinking shotgun," the officer says. 

"Hush, let me decide. Which of these sounds best? A gun that will shoot every single time you pull the trigger, even underwater or soaked in mud. A gun that hits really, really, really hard and kills things that usually take more. A gun so steady and smooth an arthritic octogenarian can shoot it five times without so much as a creaking joint."

"Probably the steady one. If I lose my footing I'm in trouble, the cane isn't decorative."

"Pistol then. Clever blowback mechanisms and springs can get the recoil down to almost nothing. I can do that."

He fishes out a wooden and obviously fake pistol from one of the many cubbies, plus a small tape measure.

"Hold that and let me get a couple measurements."