Knight encounters a troll on a bridge.
“Do I have to fight you, you hideous creature?”, said the knight.
“You won’t have to fight me if you pay the toll”
“I’m in a hurry, troll. What is the price?”
“Promise to keep the bridge safe”
“You must say it”
“I promise I will keep the bridge safe”
Gust of fog comes over the bridge, and as it clears, the knight sees a beautiful lady in front of him. Then, terrified, realizes he turned into a troll.
“Thanks, I’ve been here a long time” says the lady and leaves.