In a moment Dr. Hartmann came in, glancing at him sharply. "Good-morning, sir," he remarked, in French. "You wish to see me?"
The detective took a card-case from his pocket and tendered the doctor a card. It was one of many which he carried for such emergencies, and bore the name of Stephen Brooks.
"Yes," he said, pleasantly. "I came to consult you concerning a curious case."
"Indeed!" The doctor looked at the card carelessly. "I see that you are an American." He began to speak in English. "Sit down, please."
"Thank you." Duvall took a chair.
"What is the nature of the case, may I ask?"
"Doctor—I've heard so much of your wonderful cures—of your remarkable success in treating mental disorders, that I have ventured to come to you in the hope that you may be able to help me."
The doctor smiled, not displeased at the other's flattery. "What is the cause of your trouble, Mr. Brooks?"
Duvall observed him thoughtfully for a moment. "If a person has delusions upon one particular subject, is he on that account necessarily insane?"
"Not at all. Manias of various sorts are not uncommon, and generally curable. Why do you ask?"