You've done great up until now! I'm glad to be working with a team such as yourselves!
Now, what every story needs, is the setting of the situation. Somewhere the story can start. It'd be best if we chose Ankh-Morpork for this.

Ah, Ankh-Morpork! The Big Wahoonie ! The biggest, oldest and grubbiest city in the Discworld!
Terry Pratchett made it look a bit like the old London.

Motto of the city: Quanti canicula ille in fenestra (How Much is That Doggie in the Window) and Merus in pectum et in aquam (Pure in Heart and Water) .
Ankh-Morpork is famous for its river: the Ankh. Its water is so full of mud, dirt, and other things that it is said that "even an agnostic could walk across the water".
The citizens of the city are rather proud of this fact. They even say that "it is easier to suffocate than to drown in the Ankh".