On his day Dr. Jan Bergmann opens his new surgery he waits eagerly for the first patients to appear. But the inhabitants of Deekelsen seem more skeptical about his abilities than he had imagined - because the waiting room remains stubbornly empty. Even Jan’s own father, Professor Heinrich Bergmann, phones specifically to inform his son that any success in this venture would surprise him greatly. Professor Bergmann would far rather that Jan returned to his clinic in Hamburg. In contrast, Gertrud Hinnerksen does her best to cheer up her new boss and reassures him that until the patients arrive, all he really needs is a bit of patience.
Finally Herr Weber and Director Kranz call on the new country doctor and announce they are his first patients -- but Jan’s delight at this development is short-lived; when he examines them he quickly establishes that they are feigning their symptoms. They just want to test the new man. Jan finds it hard to conceal his disappointment at this. But then suddenly a mule appears in the yard outside. Who does it belong to? And what is he supposed to do with the animal, which proves to be proverbially stubborn and refuses to budge? When a farmer called Jens Halling turns up a little later complaining of stomach ache, Jan initially suspect that this is another test. It doesn't take him long to realise that has made a mistake, but before he can apologise to Halling, the farmer storms off back to his field. In the meantime, Gertrud calls the police officers Sven Olsen and Dieter Pätz and asks them to help with the mule. But Jan Bergmann and Olsen immediately rub each other up the wrong way, and the police officers leave without making the mule move a single inch.
A visit from Doris Jantzen and her daughter Maren proves to be a bright spot in Jan’s day. Apparently Doris Maren has been so eager to show her daughter she has everything under control that she hasn't said anything about some bad pains she's been suffering. When Maren discovers this she immediately brings her mother to see the new doctor - naturally due to her understandable concern for her mother, and not really because she wants to see the charming Dr. Bergmann again. Florian Jantzen also comes along, just to be on the safe side: after all, he also wants to make sure his mother is doing fine. The fact that he can also act as a mule-whisperer on this occasion causes him diabolical delight and costs Jan Bergmann €5 in a lost bet.
Shortly afterwards, when Jan gets a call from Ines Halling, he realises that this could be serious. He sets off immediately and manages to avert a catastrophe only at the very last second.