Southbound subway trains run fast, especially when the rush of traffic is northward. Within the hour Judson Green sat in the reading room of his club, industriously turning the pages of the club's file of the _World_ for the past month. Presently he found what he was seeking. He read a while, and for a while then he took notes. Pocketing his notes, he ate dinner alone and in due season thereafter he went home and to bed. But before this, he sent off a night lettergram to the Byrnes private detective agency down in Park Row. He wanted--so in effect the message ran--the best man in the employ of that concern to call upon him at his bachelor apartments in the Hotel Sedgwick, in the morning at ten o'clock. The matter was urgent, important--and confidential. If the man who knocked at Green's sitting-room door that next morning at ten was not the best man of the Byrnes staff he looked the part. He was square-jawed, with an appraising eye and a good pair of shoulders. He had the right kind of a name for a detective, too. The name was Cassidy--Michael J. "Mr. Cassidy," said Judson Green, when the preliminaries of introduction were over, "you remember, don't you, what the papers said at the time of the Steinway murder about the suspect Maxwell, the old man's nephew--the description they printed of him, and all?" "I ought to," said Cassidy. "Our people had that case from the start--I worked on it myself off and on, up until three days ago." From memory he quoted: "Medium height, slender, dark-complected, smooth-faced and about thirty-one years old; a good dresser and well educated; smokes cigarettes constantly; has one upper front tooth crowned with gold--" He hesitated, searching his memory for more details. "Remember anything else about him that was striking?" prompted Green. "Let's see?" pondered Mr. Cassidy. Then after a little pause, "No, that's all I seem to recall right now." "How about his being a patron of moving pictures?" "That's right," agreed the other, "that's the only part of it I forgot." He repeated pretty exactly the language of the concluding paragraph of the official police circular that all the papers had carried for days: "Formerly addicted to reading cheap and sensational novels, now an inveterate attendant of motion-picture theatres." He glanced at Judson Green over his cigar. "What's the idea?" he asked. "Know something about this case?" "Not much," said Green, "except that I have found the man who killed old Steinway." Forgetting his professional gravity, up rose Mr. Cassidy, and his chair, which had been tilted back, brought its forelegs to the floor with a thump. "No!" he said, half-incredulously, half-hopefully. "Yes," stated Mr. Green calmly. "At least I've found Maxwell. Or anyway, I think I have."