Thanks to Blacky's oblivion, a pile of unpaid invoices is waiting for Çois Backeljau. The bailiff has little understanding of the situation and threatens to remove the entire contents. Fortunately, agent Sabrina is rather inventive and can win some time for the time being. Thérèse who is fully engaged in the preparation of her waterskiing holiday. In the meantime, a strange postal package from Zaire is being delivered to the Backeljau home. The sender appears to be "tanteke", the rich and rather eccentric sister of Thérèse.