Some time had passed when, escaping from a group engaged in what struck him as particularly stupid badinage, he sauntered toward the billiard-room, struggling with a feeling of irritation. He was generally good-humored and tolerant rather than hypercritical, but the somewhat senseless hilarity of Marple's guests was beginning to jar on him. A burst of laughter which he thought had been provoked by one of Bella's sallies followed him down the corridor, but when he quietly opened the door the billiard-room was empty except for a group of three in one corner. He stopped just inside the threshold, glancing at them, and it was evident that they had not heard his approach. Wreaths of cigar smoke drifted about the room; the light of the shaded lamps fell upon the men seated on a lounge, and their expressions and attitudes were significant. Gladwyne leaned back languidly graceful; Batley, a burlier figure, was talking, his eyes fixed on Crestwick; and the lad sat upright, looking eager. Batley appeared to be discussing the principles of operating on the stock exchange. "It's obvious," he said, "that there's very little to be made by waiting until any particular stock becomes a popular favorite--the premium equalizes the profit and sometimes does away with it. The essential thing is to take hold at the beginning, when the shares are more or less in disfavor and can be picked up cheap." Lisle stood still--he was in the shadow--watching the lad, who now showed signs of uncertainty. "I dropped a good deal of money the last time I tried it," he protested. "The trouble is that if you come in when the company's starting, you can't form an accurate idea of how it ought to go." "Exactly," replied Batley. "You can rarely be quite sure. What you need is sound judgment, the sense to recognize a good thing when you see it, pluck, and the sporting instinct--you must be ready to back your opinion and take a risk. It's only the necessity for that kind of thing which makes it a fine game." He broke off, looking up, and as Lisle strolled forward with a glance at Crestwick, he saw Batley's genial expression change. It was evident that the idea of being credited with the qualities mentioned appealed to the lad, and Lisle realized that Batley was wishing him far away. He had, however, no intention of withdrawing, and taking out a cigar he chose a cue and awkwardly proceeded to practise a shot. "This," he said nonchalantly, "is an amusement I never had time to learn, and I really came along for a quiet smoke. Don't let me disturb you."