"My thinkin'-apparatus is all kinked up over the whole business," puzzled Chub, "but it looks like those two handy-boys are playing the game all by themselves. One of them wrote that warning and sent it to us, then picked up his partner and slid for the hills in order to stop us if the note didn't scare us out. They're the robbers, Matt; they're the ones that lifted Fresnay's money, all right."
"Then what do they want to keep us away from Prescott for?" queried Matt. "They needn't worry about themselves. With two good horses, and their freedom, and ten thousand in gold, they could start for Mexico. Whatever we can do in Prescott needn't bother them."
"Maybe they're not able to clear out just yet."
All the speculations of the chums regarding the two notes, and the men who had recently tried to stop them, were mere guesswork. Giving up their attempt to probe the mystery, they set themselves to the task of reaching Prescott as soon as possible.
At Skull Valley, a place consisting of only half a dozen houses and the railroad-station, they halted just long enough to eat a hurried meal. There was the chance, if they tarried too long, that their enemies might attempt to get ahead of them on the road they were still to cover.
When they had finished eating, the boys went over their machines, tightened a few bolts, lighted their lamps—it was beginning to get dark—then mounted and hurried on.
From Skull Valley north they found the worst part of the road. It was on low ground, and boggy. During the present dry weather the road was passably good, but after a rain it would have been difficult for wagons to travel it, to say nothing of motor-cycles.
For the most of the way the trail tried to follow the railroad-track, dipping under high trestles and angling back and forth across the rails. It was poor up to within half a dozen miles of Prescott, and then, abruptly, it became like an asphalt boulevard, level with the track and smooth and clean right up to the ends of the ties.
It was nearly nine o'clock in the evening when the boys reached this good stretch of road, and their lamps, streaming out ahead, showed it to them clearly.
"Mighty good going for a motor-cycle race," said Chub.