“Do you trust me? Do you feel I can get you through this night?”
They looked unsure. Slowly, each nodded. One even spoke, “I believe you can get me through this night.”
“Good. I believe we can reach the morning light. Now here is what we need to do…...”
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).