As Motan said, the 'Small Marketplace' is the mobile black market of Pato City. Its location isn't constant and even the commencement and finishing times don't follow a pattern. Without a particular channel of information, even civilians who have lived in the city for several years might find it hard to discover this place. At most, they might stumble upon it by sheer luck just once. However, it doesn't really matter, as outsiders who don't know the rules would swiftly be knocked out by a blunt object by friendly locals and dumped in some alley...
In short, it was an intriguing place. At least, it was fascinating in Motan's eyes, and it was one of the reasons why he chose to remain within the city.
