Charmed - Season 3 Episode 10 -

Prue has a melody in her head and when she sees a girl humming the tune, she finds that it belongs to the ice-cream truck. Prue and Phoebe follow the girl and the trio is sucked by a vortex inside the van. They find a playground in the middle of the snow and several children hiding from The Nothing. They rescue the children and once back in San Francisco, they realize that they are demon children. Meanwhile, their father Victor Bennett returns and helps his daughters to fix the situation, capturing the dangerous demons and sending them back to The Nothing.