"Let us look at matters from what I will assume to be their standpoint," said Nick. "They probably think they are running no risk. They must believe that the murder was not witnessed and that no clue was left behind which would point suspicion in their direction. The bank-note found near the river is a clue, it is true, but Mannion, who lost the note, cannot regard it as such, for he does not know that I have the list of the notes which Cora Reesey possessed. No one knows the fact except you, Chick, Patsy, and the chief of the St. Louis police. And it is safe to assume that he is ignorant of the fact that the negro wharf porter memorized the number, when he was given the note to change, for I cautioned him against repeating his story to any one not an officer. The negro is an old resident, and his reputation is of the best. Therefore, the loss of the bank-note would mean to Mannion nothing more than the loss of an ordinary note."
"How about the railway roundhouse affair?" asked Chick.
"There is no reason to believe that either Mannion or Goloff suspect that their talk was overheard, although they may have feared that their presence there was known. Men are to be judged by their conduct. The after movements of the two criminals show to any reasoning person that they left the roundhouse in as calm a state of mind as when they entered it. So, believing themselves to be, if not absolutely safe from suspicion, yet safe enough to laugh at the idea of arrest, they have elected to remain here to complete the work which brought them from California. I was not surprised to learn from Patsy that Mannion has appeared in public. I would have been surprised had he stayed in hiding, for that act would have raised the presumption that he knew he had not covered all his tracks, and that there was a clue which would prove fatal to his peace, if the detectives should come upon it."
"If he finds out, as he may, that you are on his track, Nick, he will get cold feet in a second."
"Maybe so, Chick," returned the great detective. "And, if so, the frigidity may strike his extremities this afternoon, for I am going to call upon him."
"What! As Nick Carter?"
"Oh, no; as Juba Johnsing, the negro who failed to change the note for him. I can make up so that he will never spot the difference. He saw the wharf porter but for a few moments, as you will remember, and probably paid little or no attention to him. I'll make the ripple Chick, and there's going to be fun."
CHAPTER XIII.
NICK CARTER'S FALL.
In the afternoon Nick, disguised as a negro porter, went to L Street. Chick and Palsy had been instructed in the rôles they were to play. The house described by Patsy was found, but the carpenters and painters were not there, although the scaffolding was still in place. As the day was Saturday, Nick found an explanation for the absence of the workmen. According to union rules, every Saturday afternoon is a holiday. The sidewalk had not been cleared and there were boxes, bricks, broken boards, and odds and ends lying about. Just beyond the entrance to the stairway, and near the edge of the sidewalk, was a large hair mattress, the ticking which covered it being torn in many places.