A young American doctor was sleeping when suddenly his doorbell began to ring. It was already midnight, but what could the doctor do? He had to get up, put on his coat and go downstairs. When he opened the door, he saw a man standing with a hat in his hand. "How do you do?" said the man. "Can you come at once to a place out of town? It's quite far but you have a car and I can show you the way."
"Certainly," said the doctor. "I'm quite ready. I can come at once." After a few minutes the car was standing at the front door, the man got into the doctor's car, and they drove off. They drove on for a long time. Then the man said, "Here we are. This is my home. Now I can pay you and you can go back to the town."
"I must see the patient. How can I go back without seeing the patient?"
"There is no patient," explained the man. "Nobody is ill. I live here, you see, and one must get home from a town, mustn't he? There are no taxis this time of the night, but a doctor often makes night calls, so excuse me. Here is money. Thank you, doctor. Good night."