She slightly clears her throat and lays a voluptuous cud of chewing gum upon the piano as the first notes of the accompaniment ring through the salon. As she prepares to sing, the Duchess du Bellairs grasps the arm of her ottoman in a vice-like grip, and she watches with an expression of almost anguished suspense. She scarcely breathes. Then, as Armande de Fleury, before uttering a note, reels, wavers, turns white as snow and falls dead upon the floor, the Duchess breathes a sigh of relief. The Duchess had poisoned her. Then the guests crowd about the piano, gazing with bated breath, and shuddering as they look upon the music rack and observe that the song that Armande came so near singing is "Sweet Marie." Twenty minutes later a dark and muffled figure was seen to emerge from a recess in the mullioned wall of the Arc de Triomphe and pass rapidly northward. It was no other than Tictocq, the detective. The network of evidence was fast being drawn about the murderer of Marie Cusheau. * * * * * * It is midnight on the steeple of the Cathedral of Notadam. It is also the same time at other given points in the vicinity. The spire of the Cathedral is 20,000 feet above the pavement, and a casual observer, by making a rapid mathematical calculation, would have readily perceived that this Cathedral is, at least, double the height of others that measure only 10,000 feet. At the summit of the spire there is a little wooden platform on which there is room for but one man to stand. Crouching on this precarious footing, which swayed, dizzily with every breeze that blew, was a man closely muffled, and disguised as a wholesale grocer. Old François Beongfallong, the great astronomer, who is studying the sidereal spheres from his attic window in the Rue de Bologny, shudders as he turns his telescope upon the solitary figure upon the spire. "Sacrè Bleu!" he hisses between his new celluloid teeth. "It is Tictocq, the detective. I wonder whom he is following now?" While Tictocq is watching with lynx-like eyes the hill of Montmartre, he suddenly hears a heavy breathing beside him, and turning, gazes into the ferocious eyes of the Gray Wolf. Carnaignole Cusheau had put on his W. U. Tel. Co. climbers and climbed the steeple. "Parbleu, monsieur," says Tictocq. "To whom am I indebted for the honor of this visit?" The Gray Wolf smiled softly and depreciatingly. "You are Tictocq, the detective?" he said. "I am." "Then listen. I am the murderer of Marie Cusheau. She was my wife and she had cold feet and ate onions. What was I to do? Yet life is sweet to me. I do not wish to be guillotined. I have heard that you are on my track. Is it true that the case is in your hands?" "It is." "Thank le bon Dieu, then, I am saved." The Gray Wolf carefully adjusts the climbers on his feet and descends the spire. Tictocq takes out his notebook and writes in it. "At last," he says, "I have a clue." * * * * * *