There was once a hunter who lived in the woods.
One day, the hunter went out to check his traps, and he discovered there was a tiny demon caught in one.
“Please, release me!” the demon begged. “If you do, I’ll tell you where to find a great treasure!”
The hunter spent some time thinking this over, and then let the demon go. He was rewarded with directions to a secluded spot in the forest.
But when the hunter went to the spot later, there was nothing there.
And that’s the joke. The punchline is implied.