Uncle Loko is frightened at night in his den and sees, to his dismay, how a huge truck discharges a stinking soap in the brook. Only the next morning it turns out how big the disaster is: a dirty, yellow poisonous mirage lies like a suffocating blanket on the water, floats downstream in the direction of the Zwarte Beek and threatens not only mother Moorhen and her newly picked chicks, but also the Boergooien, where it is teeming with moorhen nests!
Uncle Loko immediately sounds an alarm. Grandpa Kakadoris calls an emergency meeting to prevent an even greater disaster, while Piepel and Soeza are sent out to warn everyone in the Boergooien of the imminent danger. No harmless assignment, as it turns out soon …