"You get your notion about spies from ten cent thrillers," continued John Dene scornfully. "Don't you worry about me. If there's a hungry dog I believe in feeding it," he added enigmatically. "I might as well be a lost baggage office. Every mutt that has ten minutes to waste seems to blow in on me. You're the tenth this a.m." "At that rate you will soon have exhausted all the Government Departments," said Colonel Walton with a smile. "I doubt if any will venture a second visit," he added quietly. John Dene glanced across at him quickly. "Say, I didn't mean to make you mad," he said in a conciliatory tone; "but all this rattles me. I can't get along with things while they're playing rags on my 'phone. It makes me madder'n a wet hen." "I quite understand, Mr. Dene," said Colonel Walton, with that imperturbable good-humour that was the envy of his friends. "You are rather valuable to us, you see, and if we err on the side of over-caution----" He paused. "Sure," cried John Dene, thawing under the influence of Colonel Walton's personality, then after a pause he added. "See here, your boys seem to have a notion that I'm particular green goods. You just let one of 'em try and corral me one of these nights, and when you've explained things to the widow, you can just blow in here and tell me how she took it." "It's the insidious rather than the overt act," began Colonel Walton. "The what?" John Dene looked at him with a puzzled expression. Instead of replying Colonel Walton drew from his right-hand pocket something in a paper bag, such as is used by confectioners. This he placed upon the table. He then extracted from his other pocket a small package rolled in newspaper, which he laid beside the paper bag. John Dene stared at him as if not quite sure of his sanity. "Perhaps you will open those packets." With his eyes still on his visitor John Dene picked up the paper bag and, turning it upside down, shook out upon the table a brown and white guinea-pig--dead. Dorothy drew back with a little cry. "This some of your funny work?" demanded John Dene angrily. "There's still the other parcel," said Colonel Walton, his eyes upon the small roll done up in newspaper. Very gingerly John Dene unrolled the paper, Dorothy watching from a safe distance with wide-eyed curiosity. "Gee!" he muttered, as a large dead grey rat lay exposed, its upper lip drawn back from his teeth, giving it a snarling appearance. He looked interrogatingly at Colonel Walton. "There; but for the grace of God lies John Dene of Toronto," he remarked quietly, nodding in the direction of the two rodents. "Here, what the hell----!" began John Dene, then catching sight of Dorothy he stopped suddenly. "Two days ago you ordered for lunch ris de veau and apple tart--among other things. The rat is the victim of the one, the guinea-pig of the other." Dorothy gave a little cry of horror. John Dene looked across at her quickly, then back to Colonel Walton.