She told the chauffeur to go to Riverside Drive. Then, waving her hand to Nick, as the taxi glided away, she sank back in the seat and seemed to give herself up to her own thoughts. Another taxi drove up for the detective, and he told the man to take him to his home in Madison Avenue. On the way, he glanced at his bruised knuckles and smiled calmly. “Rather jarred my fist,” he muttered. “But I think I jarred that fellow’s jawbone worse. I don’t know who Prince Marcos is. But I think he was in luck when Corliston got our costumes mixed. Those two fellows meant mischief to-night if they had caught the real Marcos.” When he got home and was in his library, he threw off the Mexican jacket, glad to get rid of it. Something glittering fell from one of the sleeves and dropped upon the floor. “Hello! What have I won?” he exclaimed, as he stooped to pick up the object. “A jeweled watch! It must be worth three or four thousand dollars, I should say. That certainly was a swell crowd at the Supremacy to-night. These diamonds and rubies on the watch are magnificent, and the watch alone is a fine one in itself.” It was indeed a splendid thing. It was incrusted with diamonds and rubies. All were large, and three of the diamonds were of exceptional size. Attached to the watch was a fob of black ribbon, with a jeweled cross attached. Nick Carter remembered his scuffle with the taller man, and he had no doubt that the watch had become entangled in his sleeve at that time. “Well, when I see him again, I’ll give it back. But I am not inclined to run after him.” He dropped the watch and fob into the drawer of his big table and locked the drawer. Then he went to bed. Looking into Chick’s room on his way, he saw that his assistant was snoring away, in utter unconsciousness that anybody had opened the door. CHAPTER III. SUSPECTS AND SUSPECTS. “I am sorry to trouble you, Mr. Carter. But the loss of this watch at the ball really becomes a personal matter with me.” Nick Carter, sitting in the luxurious boudoir of Mrs. Clement van Raikes, two mornings after the great ball at the Hotel Supremacy, bowed, without speaking. “It was my ball,” went on the lady. “As one of the acknowledged leaders in New York society, I was anxious that it should be perfect in every way. It was the first fancy-dress affair I ever had given, and I had spared no pains to make it everything it should be.” “It was a brilliant ball, Mrs. van Raikes,” put in the detective. “I can testify to that personally, for I dropped in for a few minutes.” “Indeed? I am glad to hear that, because it may help you in tracing this valuable watch. Of course, intrinsically it would not be of sufficient importance for me to engage the services of the most famous detective in America, nor would you consider it on those grounds.”