Blackout
The captain narrows his eyes. He strides forward. Picks up the gem and reads the note which simply says "Bribe." He clicks his teeth and eyes the door in contemplation. Finally he whirls around and addresses his platoon. 
"Men, it appears we have been mistaken. There are no offworlders here. We march for Shadowhold." The knights look at each other then shrug and sheath their swords. The platoon marches back the way they came.