Hanni and Nanni have their difficulties with the customs of St. Clare. Above all, they find it difficult to subordinate themselves to their elders and serve them. The sports team captain, Belinda Towers, calls the twins in. Hanni misbehaves and is grounded. However, the twins manage to skilfully get around this because they look so much alike. One day, Hanni is called in by Belinda. Despite her thick skull, she is to be called up for an important game. And that fundamentally changes her attitude towards St. Clare.