When I was a child I would always rent this one particular movie from the library and I only remember bits and pieces. It was about this boy that ended up in a castle I think somehow and he unlocks this door and unleashes this black type of monster. I don't remember if it was smoke or just a blob. But it sallows up one of the main guys and then the boy has to put the mysterious black thing back where it came from. ANY HELP!? /
