Kai Haferkamp is developing into a specialist in converting children's literature into games.

The game picks up the storyline about the players, on the stroke of midnight, spending the witching hour flitting through the dark halls of Castle Eulenstein with the little ghost. Whenever the great clock in the city hall marks the passing of another hour, a picture shows up in one of the viewing windows. Whatever is shown on the picture is what the children must now find behind the closed doors of the castle.

They accomplish this with the help of a mysterious magnetic set of keys that, as if through the hand of a ghost, opens the doors of the old castle. For each correctly-opened door one receives a gleaming cannonball.

How many of these balls will be required for victory is decided only by the final dexterity game in the knight's hall.