Punctually at nine o'clock the doctor arrived. Though his hair was grey, his face was still fresh, and his eyes were lively and kind. When he saw his friend, he laughed aloud and said: "Well, well, you look pretty healthy for one who needs to be watched all night." "Have patience, my old friend," replied Mr. Sesemann. "I am afraid the person we have to sit up for will look worse, but first we must catch him." "What? Then somebody _is_ sick in this house? What do you mean?" "Far worse, doctor, far worse. A ghost is in the house. My house is haunted." When the doctor laughed, Mr. Sesemann continued: "I call that sympathy; I wish my friend Miss Rottenmeier could hear you. She is convinced that an old Sesemann is wandering about, expiating some dreadful deed." "How did she make his acquaintance?" asked the doctor, much amused. Mr. Sesemann then explained the circumstances. He said that the matter was either a bad joke which an acquaintance of the servants was playing in his absence, or it was a gang of thieves, who, after intimidating the people, would surely rob his house by and by. With these explanations they entered the room where the two servants had watched before. A few bottles of wine stood on the table and two bright candelabra shed a brilliant light. Two revolvers were ready for emergencies. They left the door only partly open, for too much light might drive the ghost away. Then, sitting down comfortably, the two men passed their time by chatting, taking a sip now and then. "The ghost seems to have spied us and probably won't come to-day," said the doctor. "We must have patience. It is supposed to come at one," replied his friend. So they talked till one o'clock. Everything was quiet, and not a sound came from the street. Suddenly the doctor raised his finger. "Sh! Sesemann, don't you hear something?" While they both listened, the bar was unfastened, the key was turned, and the door flew open. Mr. Sesemann seized his revolver. "You are not afraid, I hope?" said the doctor, getting up. "Better be cautious!" whispered Mr. Sesemann, seizing the candelabrum in the other hand. The doctor followed with his revolver and the light, and so they went out into the hall. On the threshhold stood a motionless white form, lighted up by the moon. "Who is there?" thundered the doctor, approaching the figure. It turned and uttered a low shriek. There stood Heidi, with bare feet and in her white night-gown, looking bewildered at the bright light and the weapons. She was shaking with fear, while the two men were looking at her in amazement. "Sesemann, this seems to be your little water carrier," said the doctor. "Child, what does this mean?" asked Mr. Sesemann. "What did you want to do? Why have you come down here?" Pale from fright, Heidi said: "I do not know." The doctor came forward now. "Sesemann, this case belongs to my field. Please go and sit down while I take her to bed."