Arnold (Max Riemelt) believes from childhood that he is an alien. Day in and day out, he tries to build a flying machine that will finally take him „home“. Protected by his mother Ida (Katja Riemann) and her long-time admirer, the country doctor Emil (Armin Rohde), he is considered a quirky but lovable outsider in his home village. But when a child is injured in an accident, the villagers blame Arnold’s „condition“. The young man is admitted to the psychiatric department of the state hospital. Because the young doctor Wanda (Anneke Kim Sarnau) is anyway looking for a topic for her doctoral thesis, she takes on Arnold. However, the closer Wanda gets to know Arnold, the more her world view gets confused. Not only is the doctor falling in love with her patient. In his alleged clinical picture, she also encounters inconsistencies that seem to contradict all scientific findings. Is Arnold just a „strange saint“ or could the impossible be possible? Is Arnold really a visitor…?