Heldon Foyle put his whistle between his teeth and gripped the heavy chair with both hands. As the rush came he blew the whistle three times in the peculiar arrangement of long and short blasts that is the special police call, and swung the chair down with all his force on the leading man. It was Keller. The gaming-house keeper dropped, stunned, and the detective swept the chair sideways and so forced a clear space about himself. Again the whistle thrilled out, and Ivan dodging sideways seized one of the legs of Foyle's unwieldy weapon. Menacing faces besieged the detective on all sides. Other hands assisted the Russian to hold the chair. And still no help came. Once the door opened and the wrinkled leathern face of a Chinaman protruded through the slit, took in the scene with quick understanding and disappeared. That was all the notice taken of the row by the habitués of the opium den on the high floor. The two or three clients who were stretched on the low couches were either entirely under the influence of the drug or too listless to worry about anything short of an earthquake--if even that would have aroused them. It was with small hope that the superintendent sounded his whistle again. A heavy blow on the face laid open his cheek, and he saw the little red-headed man who had slipped on his heavy brass knuckle-duster dodge back into the crowd. He relinquished his hold of the chair and defended himself with his hands. He carried a pistol in his pocket, but, imbued with the traditions of the London police, he would not use a lethal weapon save in the last extremity. Inch by inch he sidled along the wall, fighting all the while until he reached the corner. Here the crowd could only come at him from the front. A knife was thrown and a bottle crashed against his shoulder. The crisis had come. He dropped his guard and his hand closed over his pistol. Those nearest to him recoiled as the muzzle was thrust into their faces. "He daren't shoot," insisted a voice which Foyle recognised as that of Ivan. In fact, the gibe was partly true. The detective had himself well in hand, and he knew that even though he were justified, a wounded man would lead to an inquiry which at the very least would prevent his going on with the Grell investigation for some time. But to let the taunt pass would invite disaster. He dropped the weapon to his thigh, forefinger extended along the barrel to help his aim, and pressed the trigger with his second finger twice. The reports were deafening in the confined space of the room, and one man put his hand to his head with a sharp cry. He need not have disturbed himself, for the bullets had passed over him and were buried in the opposite wall. "We'll see whether I daren't fire," said Foyle grimly. "Come on. Who'd like to be the first?"