Uncle Von Pressburg's mysterious will changes the whole course of the household, where the servant Alfred takes care of the children Christine and Oliver. The children are threatened with boarding school, but in his will, the uncle decides that the children will be cared for by guardians and, in order to give them something to live on, he offers them the opportunity to set up the world's first ghost rental company. The children make friends with the ghosts, unlike their overbearing siblings who can't get along with anyone on good terms. To make matters worse, two world-famous thieves break into the basement.