Nor did the riders pass the herd in the night.  Blackburn threw an extra guard around the cattle, making the shifts shorter and more frequent; and when daylight came a short conference among the Circle L men disclosed the news that no riders had passed.  If any riders had passed the cowboys must have seen them, for there had been a moon, and the basin afforded in the vicinity of the herd, was clear and unobstructed.

Enraged at the suspicious nature of the incident, Blackburn took half a dozen cowboys and rode back, while the remainder of the trail crew sent the herd eastward.  It was late in the afternoon when Blackburn returned, disappointed, grim, and wrathful.

“There’s a bunch trailin’ us, all right,” he told Lawler; “about a dozen.  We seen where they’d stopped back in the canon a ways—­where Garvin said he’d seen ’em sneakin’ back.  We lost their tracks there, for they merged with ours an’ we couldn’t make nothin’ of ’em.  But at the foot of the slope we picked ’em up again.  Looks like they separated.  Some of them went north an’ some went south.  I reckon that durin’ the night they sneaked around the edge of the basin.  It’s likely they’re hidin’ in the timber somewhere, watchin’ us.  If you say the word I’ll take some of the boys an’ rout ’em out.  We’ll find what they’re up to, damn ’em!”

“As long as they don’t bother us we won’t bother them,” said Lawler.  “It’s likely they won’t bother us.”

Again that night the men worked in extra shifts; and the following morning the herd climbed out of the basin and straggled up a narrow trail through some foothills.  At noon they passed through a defile between two mighty mountains; and when twilight came they had descended some low hills on the other side and went to camp for the night on a big grass level near the river they had followed for three days.

The level upon which they camped was much lower than the floor of the big basin, for the water from the river came tumbling out of a narrow gorge between the hills through which the herd had passed.

They were in a wild section, picturesque, rugged.  There was plenty of water; and Blackburn and Lawler both knew that there would be water enough for the herd all the way to Red Rock.  There was a section of desert before them, which they would strike before many days; but they would cross the desert in one day, barring delay; and there seemed to be no reason why the long drive should not prove successful despite the mountain trails—­most of them hazardous—­through which they must still pass.

And yet the men were restless.  The continued presence of an invisible menace near them, disturbed the men.  They had not seen the mysterious riders again, but there was not a man in the outfit who did not feel them—­not a man but was convinced that the riders were still trailing them, watching them.

Long ago the younger men had ceased to laugh and joke.  During the day they kept gazing steadily into the gulf of space that surrounded them, carefully scrutinizing the timber and the virgin brush which might form a covert; and at night they were sullen, expectant; every man wearing his gun when he rolled himself in his blanket.