"What makes you go certain this man is a Chicago detective?" asked Will. "I haven't seen anything that looks like Chicago about him!"
"Why," answered Tommy, "he's mentioned Harrison street and Desplaines street and Chicago avenue half a dozen times when talking about the police department of Denver! And he's been telling about police boats on the lake and on the North and South branches and giving himself away generally. Of course, he doesn't know we're from Chicago and so he doesn't think it necessary to be careful in his speech."
"All right, time will tell!" exclaimed Sandy.
It was arranged that Will, Tommy and George were to sleep together in one of the tents until midnight while Tommy stood watch, and from that time on, the other boys were to watch two hours apiece. Katz was to have the second tent all to himself.
For sometime after the lads and Katz went to their tents, Tommy sat by the fire listening to coyotes and grey wolves howling off in the mountains. Occasionally a coyote came within a few paces of the fire and set up a howl which must have been heard in the dreams of the sleepers.
Along near midnight the boy heard, very indistinctly, shouts to the west of the ridge which lay to the south of the valley. Still more faintly, return shouts were heard. The men, whoever they were, seemed to be advancing toward the camp. While the boy listened a volley of shots came from the west, followed by hoarse shouts and imprecations.
It now became plain that two horsemen were speeding toward the valley and that the shots which were being fired were directed at them. There was no moon as yet although there would be one later on, and little could be seen of the horsemen who were doubtless seeking refuge in the canons farther to the north, but the heavy breathing of the horses and the creaking of the saddles could be distinctly heard.
"I just went to the tent to wake Katz!" Tommy chuckled, "and saw him sneaking away making flat-footed for the hills!"