Delaney stared at Harrigan. Drew swung to his desk and tapped the blotter for a moment. "We'll get busy," he said briskly, as he swung back again and faced the two operatives. "I've almost got my man. That bird there," Drew pointed toward the magpie, "is our one best bet and lead. I may be wrong, but I'll wager a good cigar there's a convict or ex-convict at the back of this case. How else can we explain 'Ossining' or 'Ah, Sing' repeated through the magpie to us. It's not an impossible clue. It might happen. Let's move with both feet!" Delaney rose lankily and stood by the door. He braced his shoulders, then shelved them forward as he reached a finger toward the bird-cage. "Pretty Poll!" he said. The magpie darted about the cage like a shaft of blue light. It came to rest with its tail feathers thrust through the bars. It peered with beaded eyes at Drew who had snatched up a bundle of papers and was sorting them. "Get busy, Delaney, on this assignment!" he said sharply. "Waste no time. Run up to Stockbridge's and get me plaster-paris casts of all the footprints you can find around that junction box. It's stopped snowing," he added, glancing out the window. "All right, Chief." "Wait a minute. Stop somewhere on your way up-town and find out the exact temperature changes last night. What I want you to get is a record of every quarter-hour, so as to show when the early, packed snow in Stockbridge's yard froze solid. The under crust!" "I got that in my head, Chief! That's my idea, exactly. If a tall lad tapped in on the junction box early in the night his footprints will be frozen close to the ground. The whole surface is level now, but there ought to be ice-posts sticking up when I get done thawing." "That's right! You'll probably find the trouble-hunter's and one other set of prints. The other set is our man's!" "What size feet did the trouble-hunter have?" "Small--about six!" "All right, Chief, I'm off." "Walt a minute." Drew studied a sheet of paper. "After you get the temperature data, Delaney," he said. "After you get that and the plaster casts of the footprints, go into the house and stay there. Watch Miss Loris. Don't talk to Fosdick's men. Tell her to be careful. Tell her that she is in grave danger. Remember that the same man who threatened Stockbridge over the wire, also said he was going to get her. Remember that, Delaney!" "Good-by!" "Get a shave!" shot Drew out through the closing doorway. "I'll do that little thing," came echoing back with a hearty chuckle. "Now, Harrigan," Drew said, shuffling the slips of paper like a deck of cards. "Now, we're closing in on our man or men. See if you can find Frick at the prison. 'Phone from the booth!" Harrigan was back within three minutes. He leaned over Drew. "Frick was with the warden," he whispered tersely. "He was easy to get. He says that Morphy has been trying to telephone----" "What?" "Tryin' to telephone, Chief----"