30 pistols, rifles, and assault weapons
The commericaly available firearms of the Cosmic Era
The basics of magnetic weaponry in the Cosmic Era
Drawn from the rather generic Gunslinger Adept from Shadowrun, but influenced very strongly by the 2002 film Equilibrium and the 2008 Wanted.
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).