Warrenheim, an enthusiastic plant lover, moves with his daughter Hansi and gardener Valentin to the neighboring property of animal lover Adele Hecht and her maid Lisl. At first, the new neighbors get along well, but the peace is soon disturbed: Adele's poultry, including a supposed “Siamese duck” that allegedly lays only one egg per year and is supposed to be the basis for Adele's breeding plans, eats Warrenheim's plants. In the course of the dispute, they insult each other and each seek legal action. Meanwhile, Hansi and Theo grow closer, but the neighborhood dispute overshadows their relationship, and Theo's aunt continues to try to set him up with Irma. A reconciliation meeting is scheduled to settle the dispute. The meeting begins turbulently with mutual accusations. Theo is able to clear up the misunderstanding with a comment unrelated to the matter at hand and win back Hansi's affection. Just as the lay judge seems close to despair, the duck they brought with them lays another egg, which is widely regarded as a miracle and contributes to the general reconciliation. Three couples leave the room: Adele and Warrenheim, Theo and Hansi, and Lisl and Valentin.