"Well for one thing," Drew said, lifting the third photo. "For one thing, we know that our man passed through the doorway before or after the murder. He was in the library. He was in that booth which is a half mile or more away from the mansion." "I'll grant you that, but what does it prove?" Drew laid the photo on the table and turned toward the doorway. "It proves," he said, "that Stockbridge was murdered by a man who was never arrested in New York." "That's a large order!" chuckled the commissioner. "There are a few good citizens and a number of bad ones we haven't got--yet!" "I'm satisfied," said the detective, pulling his hat down over his head. "I'm going to look for a man who is too clever for his own good. He's stayed out of your clutches. He's forgotten more about telephones than most men know. He's as slippery as an eel and as clever as the very devil. In one thing only did he err, so far in this chase." "What's that?" asked the commissioner. "He didn't wear gloves on the job. That's where we may trip him up." "They all forget something," said Fosdick, as Drew hurried out through the door with a bow toward the staring fingerprint man. The detective hurried down the steps,--passed the sergeant at the entrance, and turned up his coat collar as he plunged from the building and lowered his head beneath the down driving snow. The entire matter was as he had told Delaney. He would have to find who made the prints! Deep, drifted snow barred his progress as he struck down through a towering cañon and walked eastward. He had no coherent idea save the one that he wanted the grip of the open places in his lungs and the feel of freedom from stifling rooms and skeptical men. The case had resolved itself into a battle of wits wherein the culprit who had murdered Stockbridge, by unknown means, had all the advantages. He was unknown. He had the largest city in the world to hide himself in. He could strike at any time and in any quarter. Also, the detective realized, with a chilly oath, the murderer might already be fleeing the city for the south or west. It would be a natural thing for him to do. Drew had one undisputed qualification for a detective. He was a worker. He lacked the Latin sense of deduction, or the cleverness of a great operative who secured his men through quick brain work and shrewdness. Hard work, and more work and still more work had won for him the little position he held in the city. He did not overrate his own powers. He had failed too often to hold himself too highly. Chance was a big factor in the criminal game. The members of the criminal tribe worked through luck and sheer audacity. Many escaped from the net and moved in the underworld until they made their final mistake which was probably so glaring it couldn't be overlooked.