Toltep walked slowly along the avenue, it would have been easier to swim along in the viaduct, but he had made it a point to not do the easy thing. All to often the easy path lead to ruin, and he had not survived so long by taking shortcuts, or the easy road. The market, what was above water, was abuzz with conversation. A large school of blood-crazed lurdi had been diverted into an ambush where the brave people had slaughtered the monsters. There was some worry, Toltep gathered, as a few had escaped.
The player characters, experienced and somewhat well known, hear rumors and travelers' tales about a distant area being overrun by dragons (or other terrifying monstrosities). The locals have sent them a message, begging for heroic aid.
When they investigate, they discover that nothing of the sort is going on. It turns out that a group of thieves wanted them out of the way so that they could rob them (or someone who would normally receive their protection).