Time travel in the footsteps of ancient vegetable varieties: Mette and Theo with the poet Goethe. A burglar has devastated Alma's secret garden, where she cultivates the original plants of old vegetable varieties. Mette and Theo travel back in time with the magical tulip tree to the origin of the plants to bring back new seeds. This time, they need to find the seeds of the evening primrose and end up with the tulip tree at Goethe's in Weimar. However, even the great poet has never heard of an evening primrose. Where are they supposed to get the seeds now? Without them, they can't return to their own time. Fortunately, Goethe's son Gustel comes to their aid.