"I only hope that nothing may occur to mar your pleasant lives, my dear fellow," he said, slowly knocking the ash from his cigar. "In the marriage state one never knows whether adversity or prosperity lies before one." "I hope I shall meet with no adversity," I said. "I hope not--for Sylvia's sake," he declared. "What is for Sylvia's sake?" asked a cheery voice, and, as we both looked up in surprise, we found that she had re-entered noiselessly, and was standing laughing mischievously by the open door. "It is so dull being alone that I've ventured to come back. I don't mind the smoke in the least." "Why, of course, darling!" I cried, jumping from my chair and pulling forward an arm-chair for her. I saw that it was a bright night outside, and that the autos with their sparkling lights like shooting stars were passing and repassing with honking horns up and down the Rue de Rivoli. For a moment she stood at my side by the window, looking down into the broad thoroughfare below. Then, a second later, she suddenly cried-- "Why, look, Owen! Do you see that man with the short dark overcoat standing under the lamp over there? I've seen him several times to-day. Do you know, he seems to be watching us!" "Watching you!" cried her father, starting to his feet and joining us. The long wooden sun-shutters were closed, so, on opening the windows which led to the balcony we could see between the slats without being observed from outside. I looked at the spot indicated by my wife, and then saw on the other side of the way a youngish-looking man idly smoking a cigarette and gazing in the direction of the Place de la Concorde, as though expecting some one. I could not distinguish his features, yet I saw that he wore brown boots, and that the cut of his clothes and the shape of his hat were English. "Where have you seen him before?" I asked of her. "I first met him when I came out of Lentheric's this morning. Then, again, when we lunched at the Volnay he was standing at the corner of the Rue de la Paix and the Rue Daunou. He followed us in the Rue Royale later on." "And now he seems to have mounted guard outside, eh?" I remarked, somewhat puzzled. "Why did you not tell me this before?" "I did not wish to cause you any anxiety, Owen," was her simple reply, while her father asked-- "Do you know the fellow? Ever seen him before, Sylvia?" "Never in my life," she declared. "It's rather curious, isn't it?" "Very," I said. And as we all three watched we saw him move away a short distance and join a taller man who came from the direction he had been looking. For a few moments they conversed. Then the new-comer crossed the road towards us and was lost to sight. In a few seconds a ragged old man, a cripple, approached the mysterious watcher with difficulty, and said something to him as he passed.