A few minutes after the inspector had entered the office his two subordinates had the surprise of their lives. A third taxi drew up at the door, and out of it stepped no less a person that Superintendent Wilson. While they were debating whether to speak to him, his quick eye caught sight of them, and, rapidly walking a little way along the street in order to be out of view, he beckoned them to come. “What are you doing here?” he asked. In a few words the men told him that Inspector Blaikie, and Joan and Ellery as well, were inside, and that they had received instructions to remain on the watch, and to follow Woodman if he came out. The superintendent thought rapidly. If he went in, it would be obviously impossible to maintain his _alias_ of Mr. Porter, and he ran the risk of interrupting a most important conversation. If, on the other hand, he stayed outside, what blunder might not be committed in his absence? Telling the men to remain on guard and follow the inspector’s instruction, he entered the building. He did not, however, go to the door of Woodman’s outer office. Instead, he went along the corridor to where, as he remembered, the private door from Woodman’s inner sanctum gave on the passage. There he paused and listened. Some one was speaking within; but not a word was audible through the stout door. There was no keyhole, and nothing was to be seen either. The superintendent must fare further, to the back of the building, if he sought to find out what was in progress in Woodman’s room. There might be a window, looking on the room, through which he could watch unobserved. He soon found a back-door, leading into a small flagged yard at the rear of the building. It was locked; but the key was in place. Unlocking it he slipped out into the yard, and easily located the window of Woodman’s room. By standing on a water-butt, he could see the three people—Joan, Ellery, and Carter Woodman—within. But the window was closed, and he could hear nothing. He remained at his post of vantage, watching. Chapter XXXVI An Afternoon Call Hardly had Joan and Ellery passed from the outer office into Woodman’s private room when the inspector entered the room they had left, and asked if Mr. Woodman was in. Moorman, who had met the inspector several times lately, saw nothing strange in the visit, and merely replied that his employer was in, but that he was at the moment engaged. “If you care to wait, sir, I dare say he won’t be long.” Blaikie said that he would wait, and Moorman thereupon suggested that he should go in and tell his principal that the inspector was there. But the inspector told him not to bother: he would take his chance when Woodman was free. He sat down, therefore, to wait in the outer office, improving the minutes by conversing with the loquacious old clerk about his employer’s affairs.