GRIMM - The Gifts of the Little People

A tailor and a jeweler are out hiking. It's late, they want to go home, but they hear a sound from one of the hills. Tones that get stronger and stronger, and turn into sweet music. The tailor and the jeweler follow the music and discover a group of little people. They party with them all night long and when they wake up the next day, their pockets are filled with gold. But the little people are gone. Who were they and how can the men find their way back to them once more?