He could barely see the form of a man walking rapidly down the street to the horse-car track.
As he passed the window of the saloon the light fell on him, and Sam saw it was one of the two men who had just left the cooper-shop.
Following closely, using all his skill as a successful shadow, he trailed the man to the car, and boarding the front platform rode into town.
Passing a livery stable the man left the car, still followed by Sam.
When Moriarity, for it was he whom Sam was trailing, rode back to the river, Sam was perched on behind the hack.
He saw the wounded Chip placed inside, thanks to the darkness, and still hanging on the back of the carriage was carried back to town.
When the two train robbers turned into the alley Sam was right behind them, so close that he could hear their labored breathing. Suddenly, as if they had been swallowed by the earth, he was left alone in the dark, nonplussed and outwitted.
Not a point of light was visible, and settling himself against the wall of a building, Sam started in for an all-night watch.
He understood the case at once. Chip had been knocked down by the renegades, and, probably still insensible, had been carried to their haunt. Knocked down, either because they had discovered his disguise, or had suspected him.
He was now firmly convinced that if Cook was not an accomplice in the train robbery, he was involved in something criminal, and Sam regretted that he had not been more thorough in his investigations. Now that Chip was in the hands of his enemies, all others sank into insignificance; so with keen eyes and sharp ears, Sam kept his solitary vigil.