Here’s a Sword Noir plot idea:
The characters were framed for various crimes and have spent the last year or more toiling at the oars of Everthorn’s merchant fleet. They are suddenly released at the behest of the Captain (leader of the Whites, the incorruptible unit within the city’s Urban Cohorts) or some other figure. They are told the same criminal boss framed each of them, and now their benefactor has decided to bring that boss down. The benefactor offers the character their freedom if they can destroy the boss and the boss’s criminal network.
Some variations:
– one character is the wrongly accused and the rest of the PC group are old associates who remain loyal OR other agents of the benefactor
– the benefactor is not a criminal, rather it is one of Everthorn’s elite, and the characters are rescued by either a political rival OR a criminal boss who wants revenge against the elite figure
– the benefactor is lying to the characters to get their cooperation, and at some point in the adventure, the characters learn the truth
You can buy Sword Noir: A Role-Playing Game of Hardboiled Sword & Sorcery here.