He extended a huge hand to Jack.

    "Any friend of Mr. Wollaston is a friend of mine," he said.

    Jack turned his attention to the table, and he had not been watching long before he saw that the game was crooked. It was the dealer who betrayed the fact—the dealer who reached out to rake in the money before he had turned the cards.

    It was only by a fraction of a second that he made the mistake, a mistake that escaped the observation of everybody except Jack. He looked round the table, and presently spotted the decoy duck—a tall, slim young man with whom Dennis had been exchanging friendly glances.

    "I'm going to have a plunge," said this youth after the game had been in progress for an hour. "What is the bank, Jackson?"

    "A hundred thousand, sir."

    The youth looked at Dennis.

    "I'll go banko if you'll stand half, Dennis," he said, and Dennis nodded. "Banko," then declared the young man.

    "Wait a bit," said a quiet voice. It was Jack who spoke, and the people at the table craned round. He was smiling.

    "I'll bet anybody here twenty thousand pounds that the bank's cards are two nines," he drawled; "who'll take me?"

    "What the dickens do you mean?"

    The big figure of Boolby elbowed a way through the press about the table.

    "I mean this is a crooked game," said Jack calmly; and, stooping swiftly, he turned the cards.

    As he had said, the bank's were two nines, which would beat anything.

    "Every fifth, sixth, and seventh coup the bank wins," Jack went on. "And that stool pigeon"—he pointed to the slim young man—"kids somebody to come in."

    By this time Boolby was facing him.

    "Get out," said Boolby curtly. "Bring that lift up, Jones."

    His hand was on Jack's arm, but the next instant he went down to the ground with a smashing blow in the face.

    Instantly there was pandemonium. Four attendants rushed at the young man: the first he picked up and flung against the wall; the second he lifted bodily above his head; and the other two stopped in their tracks.

    He took a quick glance round, then flung the man upon the green table, which collapsed with a crash under the impact, scattering cards and money in all directions.

    Then he gripped Dennis by the arm. "Come along," he said.

    "What have you done!" wailed the youth. "You have acted disgracefully, you blackguard."

    Jack released his arm and went back to Mr. Boolby, who was sitting on the floor, his hand to his swollen jaw. He jerked the man to his feet.

    "Show me the way out of this."

    "I'll kill you!" hissed Boolby, and swung his arm. Again that smashing fist struck him, this time on the body, and he gasped.

    "Show me the way out," repeated Jack; "or, better still, show me the way to your office."

    The man was breathing heavily, and it was some time before he could speak.

    "Come on," he snarled at last. "But don't forget I'll fix you for this."

    They went through to another room, and through a door, down a flight of stairs, and Dennis followed. Boolby opened the door.

    "Come in here," he growled.

    A woman was sitting in the room, and she sprang to her feet as they entered.

    "My wife. If you're a policeman, you'll know she's not in this," mumbled Boolby, but Jack was smiling at Mrs. Fanny Fleming.

    "So you're the real decoy duck, are you? I presume you're the person who gave away every attempt to save this boy. Come in, Wollaston."

    He dragged the young man into the room, and Dennis stared from one to the other.

    "Now, Boolby, you can open that safe of yours and pay over to Mr. Dennis Wollaston the money he has lost since he has been your patron."

    "I'll—" Boolby, spluttering with rage, could not find words to complete the sentence.

    "You'll do as you're told," said Jack calmly.

    "Suppose I don't?"

    Jack looked round. There was a window at the end of the apartment. He walked quickly to it, pulled the blinds, opened the lower sash, and looked out.

    "I guess that's far enough," he remarked. "You'll either do as I tell you, or I'll throw you out of that window. You doubt my ability?"

    "Oh, pay him, pay him!" It was the white-faced Mrs. Fleming who spoke. "He'll do it. I ought to have known he was a detective."

    Jack was silent, but no more silent than Mr. Dennis Wollaston, who seemed bereft of speech.