He got up, and was about to approach the safe, when there came a knock at the door, and, in response to his somewhat surly invitation, Mrs. Peters, the housekeeper, appeared on the threshold. She was dressed for the street, and had a strap wrapped about the knuckles of one hand. “I’m going to take my usual constitutional, sir,” she announced, “and I thought, if you had no objection, that I would take Prince with me. He’s been shut up in the kennel most of the time since you went away, and what he really needs is a good run.” Just then the detective’s famous police dog pushed past the housekeeper’s skirts, and pattered into the study at the end of the leash which Mrs. Peters held. The animal started eagerly for his master, as if surprised to find him there. Suddenly, however, he halted, the hair along his back raised in a bristling line, and an unmistakable snarl escaped him. “Good boy! Good old Prince!” Gordon said, in a wheedling tone, but he had turned pale, and his eyes were very ugly. “Take him by all means, Mrs. Peters. His confinement doesn’t seem to have improved his temper—and I’m busy.” But the housekeeper was staring from Prince to the man she believed to be her employer. “Well, I never expected to see anything like that!” she ejaculated wonderingly. “Don’t you know your own master, Prince? What’s the matter with you, anyway? You are not going mad, are you?” Green Eye’s hand had mechanically sought the pocket in which the automatic lay. “Oh, it’s nothing like that,” he said, with assumed lightness. “The heat has put him a bit out of temper, that’s all. Take him away, and let him work off his grouch.” Still looking very much bewildered, Mrs. Peters turned to go, but she had to drag the dog from the room by main force, and the more she pulled at the leash, the more he snarled. When the door finally closed upon them, Gordon passed a trembling hand across his forehead, and his fingers came away damp with sweat. “Curse the brute!” he muttered savagely. “If he does that again, I’ll have to put him out of the way.” He had intended to tackle the safe, but now he changed his mind once more. He was too much shaken by this last experience to attempt anything of that sort at present, and, therefore, he determined to take a walk and steady his nerves. In less than an hour he was back in Nick’s study, though, and the door was locked. He was about to try his luck with the detective’s safe. CHAPTER XIV. CRAY CALLS ON MRS. SIMPSON. It was quite early in the afternoon when Jack Cray reached New Pelham, and during his journey to that outlying suburb he had plenty of time in which to think out a plan of action, using as a basis Gordon’s suggestion that he should present himself as a fellow employee of the missing Simpson. Cray walked briskly through the little town, having inquired the direction in which Floral Avenue lay, and soon came to a steep hill.