“First floor!” said he to the boy, and they went up alone. “Wasn’t it the gentleman in No. 15 who just went up?” he asked. “No, sir; it was the Dutch Professor in No. 10.” “Ah, then my eyes must have deceived me,” he said. “Thank you;” and he proceeded slowly along the corridor. He came to No. 10, lingered a moment there, then went on and looked backward, hearing a door open. It might have been No. 10. He waited, stooping down and busying himself with his shoelace, and when he heard the door shut again, he turned round. Then he saw that on the mat in front of No. 10 there was a pair of shoes. He went back, an unusual idea having occurred to him. He would knock at the door and ask the old gentleman whether he had recovered from his indisposition, and then take him unawares, for he felt he had enough to go upon to arrest him. The idea seemed to him both a bold and promising one, but when he stood in front of No. 10 again, he saw that the shoes outside the door were women’s shoes, and he gave up the thought. Then he went downstairs and asked to see the hotel manager. He showed him the necessary credentials and asked about the gentleman in No. 10. The hotel list was brought. “No. 10, you see, sir, is Professor Grote, from The Hague.” “According to your book he is staying here alone.” “That is so, your honour.” “Is he always alone here, or now and then with a female companion?” “I do not allow anything of that sort, your honour. We are very strict about our guests’ respectability.” “Well, I can only say that this guest, in spite of his size, has uncommonly small feet.” “What does your honour mean by that?” “He wears ladies’ shoes.” “Ah now, sir, you are joking.” “Well, come with me, my good fellow, and see for yourself.” They went upstairs together. In front of No. 10 they saw a pair of elegant high-heeled shoes of the latest fashion. Then Wenk cocked his revolver and went in without the formality of knocking. He entered the room quickly, the hotel manager following him. The light was on, but the room was empty. Both the windows were closed and the bathroom adjoining had none. Wenk searched the cupboards, bed, and drawers, but nowhere was any clue to be found. He hurried down to the street, but the stranger’s car had disappeared. He made the manager inquire who had left the hotel within the last ten minutes. “Nobody but the secretary,” said the commissionaire. At that moment the secretary came from behind a partition, ready to leave the hotel. The man looked at him in amazement. “You here again! You only left a few minutes ago.” “_I_ did? I was in the bureau till this very minute,” answered the employé.