The citizens of Dunwall - home to the events of Dishonored - are subject to terrible restrictions on their personal freedom. There's a compulsory dusk-'till-dawn curfew for starters, which is vigorously applied by the city's guards. At sundown, doors and windows are bolted shut by industrial-sized clamps, and anyone who does somehow manage to wiggle past them is shot on sight.
Things don't get much better come the break of dawn. Electrified 'Wall of Light' barriers have been erected around Dunwall to control people-flow and to quarantine poverty-stricken areas from their affluent neighbours. Anyone who stumbles into the barriers is vapourised.
While the population is kettled like cattle, loudspeakers boom government-fed propaganda into their lugholes and anyone who shows the merest hint of disease is immolated in plain sight by 'Tallboys' - looming guards on mechanical stilts who tower over the quivering proletariat.
Dunwall's civil liberties have been curtailed in an attempt to contain a devastating rat plague that has derailed the once-charming maritime city's recent industrial expansion and left half the population dead.
The city's survivors - largely members of the aristocracy who can afford the immunity elixir - cling desperately to a vestige of respectability, but that's all it is - a veneer. Dishonored's world is a grim one of routine, oppression and restriction. Except for you, of course. In Dunwall, you can do anything you damn well please.
You are Covano Attano, Royal Protector to the Empress of Dunwall. Or at least you used to be before the Empress is slain before your eyes by assassins. The Empress' consort then frame you for the murder, before kidnapping the Empress' daughter and seize power in a meticulously prepared coup.
But you're no normal man, and that's why a group known as The Loyalists go to great lengths to help you break out of Coldridge Prison in what is in effect a tutorial level.
Dishonored's powers exist in a world designed to give you room to explore them to their full potential
The Loyalists are an eclectic group of activists led by the imperious Admiral Havelock. Their members span the full range of society - from aristocrats to paupers - but they're all united by a common goal; to overthrow the rogue government and reinstate the missing princess.
None of the Loyalists seem particularly trustworthy. But they seem to be your only allies in a city where loudspeakers remind everyone on the hour every hour that you're public enemy number one - so Corvo goes along with their plans for the time being.
Initially, each level sees Corvo travelling to a different district of Dunwall to incapacitate an influential member of the makeshift government. The Loyalists openly squabble over how Corvo should go about doing this, and their differences in opinion foreshadow the incredible freedom Dishonored affords you in choosing how to complete each objective.
As Corvo, you're an all-round offensive terror, equally built for stealth or slaughter. Depending on your playing style, you can go through the entire game undetected, or you can ensure every last citizen dies by your sword.
On top of that, you can augment Corvo's natural abilities by seeking out magical runes dotted around Dunwall. To help you locate them, you're equipped with this gross sentient heart thing, which offers hints and tips when you squeeze it with the left trigger. Except sometimes, it'll just say something eerie like 'Why am I so cold?' - and you'll want to drop the controller to the floor in horror.
The runes allow you to harness magic (which is outlawed in Dunwall, naturally). Depending on how you branch out your skill tree, you'll be able to teach Corvo to warp from rooftop to rooftop, or control swarms of carnivorous rat, or observe enemy movements through walls, or slow down time, or even possess any living creature in the game - from lowly fish and rats to your assassination targets themselves. If you put the hours in you can learn the entire lot, and then you've got the toolset to make Dunwall your own personal playground.
Corvo's supernatural endowments bring to mind BioShock's plasmids (which can't be a coincidence - Arkane Studios helped with design and art on BioShock 2), but unlike Irrational Games' creaky Rapture (which is beginning to show its age in design terms), Dishonored's powers exist in a world designed to give you room to explore them to their full potential.
It isn't the size of the levels that gives Dishonored scale; in fact in some areas it's relatively linear. Rather, it's how densely packed each square inch is with opportunities to problem-solve with creativity, verve and experimentation.
Every obstacle you encounter has at least three or four ways to overcome it. For every locked door, there's likely a balcony up high you can teleport to, or a gutter down below that can be infiltrated by a possessed rodent.
If these avenues aren't yet open to you, you could instead sneak into an adjacent back alley and eavesdrop on a couple of guards, who might drop details of an alternative entrance into the conversation. If not, you can pickpocket the master key from their belts while they natter, or just wash your hands of the whole thing, return to the door and bust it down with a whirlwind.