The chief tomte will help you out. He just needs more power.
Still not working
You need to free all tomtes to help him. Start from the one in the left. ( Use the dagger to free him. )
Use the dagger to free him.
One was down there when you used the mirrors. You have to climb down there.
Climb all the way up. There is one.
That's it. Go stand on that stone.
Oh, talk to them so that all four tomtes are dancing.