He led the perturbed scholar inside and got him settled in a chair. “Now, go ahead. Show me the advertisement and tell me how much you lost.” “I’ve lost my assistant. There is no advertisement about it. What I came for is advice. But upon seeing your tricky door-plate—” “Oh, that’s merely to encourage the timorous. Who is this assistant?” “Harvey Craig, a youth, hardly more than a boy, for whom I feel a certain responsibility, as his deceased parents left him in my care.” “Yes,” said Jones as the professor paused. “He has disappeared.” “When?” “Permanently, since ten days ago.” “Permanently?” “Up to that time he had absented himself without reporting to me for only three or four days at a time.” “He lived with you?” “No. He had been aiding me in certain investigations at my laboratory.” “In what line?” “Metallurgy.” “When did he stop?” “About four weeks ago.” “Did he give any reason?” “He requested indefinite leave. Work had been offered him, he hinted, at a very high rate of remuneration.” “You don’t know by whom?” “No, I know nothing whatever about it.” “Have you any definite suspicions as to his absence?” “I gravely fear that the boy has made away with himself.” “Why so?” “After his first absence I called to see him at his room. He had obviously undergone a violent paroxysm of grief or shame.” “He told you this?” “No. But his eyes, and, indeed, his whole face, were abnormally swollen, as with weeping.” “Ah, yes.” Average Jones’ voice had suddenly taken on a bored indifference. “Were—er—his hands, also?” “His hands? Why should they?” “Of course, why, indeed? You noted them?” “I did not, sir.” “Did he seem depressed or morose?” “I can not say that he did.” “Professor Gehren, what, newspaper do you take?” The scholar stared. “The _Citizen_ in the morning, The _Register_ in the evening.” “Are either of them delivered to your laboratory?” “Yes; the _Register_.” “Do you keep it on file?” “No.” “Ah! That’s a pity. Then you wouldn’t know if one were missing?” The professor reflected. “Yes, there was a copy containing a letter upon Von Studeborg’s recent experiments—” “Can you recall the date?” “After the middle of June, I think.” Average Jones sent for a file and handed it to Professor Gehren. “Is this it?” he asked, indicating the copy of June 18. “That is the letter!” said that gentleman. Average Jones turned the paper and found, upon an inside page, the strange advertisement from 74 Bellair Street. “One more question, Professor,” said he. “When did you last see Mr. Craig?” “Nine or ten days ago. I think it was July 2.” “How did he impress you?” “As being somewhat preoccupied. Otherwise normal.” “Was his face swollen then?” “No.” “Where did you see him?” “The first time at my laboratory, about eleven o’clock.” “You saw him again that day, then?”