Bethesda are publishing. Arkane did Dark Messiah of Might and Magic... Wikipedia: "Harvey Smith, known for his past work on the Deus Ex franchise as well as Thief: Deadly Shadows, and Raf Colantonio, who worked on Arx Fatalis and Dark Messiah of Might and Magic, are the lead designers on the game."

The game is set in a world that blends both the past, future, and things in-between, of our reality. Nobles ride in carriages, masses of man-eating rats lurk in the dark gutters, the sound of automated factories can be heard in the distance, and towering war-machines prowl the cobbled streets. The economy of the world, which is going well into its industrial age, is booming with the success of a useful, multipurpose fuel; Whale oil. Locations include the desolate Isles, the mighty Pandyssian Continent, and the city of Dunwall.

YT: "Dishonored casts you as a supernatural assassin driven by revenge. You are the once-trusted bodyguard of the beloved Empress. Framed for her murder, you become an infamous assassin, known only by the disturbing mask that has become your calling card. In a time of uncertainty, when the city is being besieged by plague and ruled by an oppressive government armed with strange technologies, dark forces conspire to bestow upon you abilities beyond those of any common man.

In Dishonored, creatively eliminate your targets with the flexible combat system as you combine the numerous supernatural abilities, weapons and unusual gadgets at your disposal. Pursue your enemies under the cover of darkness or ruthlessly attack them head on with weapons drawn. The outcome of each mission plays out based on the choices you make. "