passed through the station. At first I could not understand.
"I have not been sure," he was saying, "and I have told no one. I have been working on it for weeks, and I cannot make sure. Watch out for Knowlton. I suspect him. He knows the secrets of a score of our refuges. He carries the lives of hundreds of us in his hands, and I think he is a traitor. It's more a feeling on my part than anything else. But I thought I marked a change in him a short while back. There is the danger that he has sold us out, or is going to sell us out. I am almost sure of it. I wouldn't whisper my suspicions to a soul, but, somehow, I don't think I'll leave Chicago alive. Keep your eye on Knowlton. Trap him. Find out. I don't know anything more. It is only an intuition, and so far I have failed to find the slightest clew." We were just stepping out upon the sidewalk. "Remember," Hartman concluded earnestly. "Keep your eyes upon Knowlton."
And Hartman was right. Before a month went by Knowlton paid for his treason with his life. He was formally executed by the comrades in Milwaukee.
All was quiet on the streets—too quiet. Chicago lay dead. There was no roar and rumble of traffic. There were not even cabs on the streets. The surface cars and the elevated were not running. Only occasionally, on the sidewalks, were there stray pedestrians, and these pedestrians did not loiter. They went their
