AllMovie

While cavorting around in the ruins of a castle in Prague, a trespassing gang of boys encounter a ghost from the days of knighthood. Naturally enough, they are scared by him. However, when the ghost is caught in a trap set by some other interlopers, they rescue him, and they become allies in a fight to prevent the glorious ruins from being turned into a mushroom farm by the city authorities. Thanks to the involvement of the knight, forest elves are brought in to help their cause.