Sir Sneezeworth had one significant professional disadvantage: he was allergic to dragons.
Not mildly allergic. Explosively, magnificently, unstoppably allergic. Within twenty feet of a dragon, he would sneeze with the force of a small catapult.
This was a problem, given his career choice.
The king sent him to deal with the dragon in the mountains with a straight face and what Sir Sneezeworth strongly suspected was suppressed laughter.
He approached the cave with his visor down, breathing through his mouth.
"Halt," he managed, "in the name of— ACHOO."
The sneeze was so violent it knocked him backwards off his horse.
The dragon peered out of the cave, baffled.
Sir Sneezeworth got up. "SURRENDER OR — ACHOO."
He knocked over a tree.
The dragon started laughing.
Sir Sneezeworth stood in the wreckage of the tree, covered in leaves, visor askew, nose streaming.
"Are you quite all right?" said the dragon.
"Perfectly," said Sir Sneezeworth with great dignity. "ACHOO."
He knocked over his own horse.
The dragon laughed so hard it started crying. Then it agreed to stop terrorising the village, purely because it hadn't laughed like that in three hundred years.
Sir Sneezeworth claimed full credit for the negotiation.