The men stared at each other for a moment; then followed the doctor in a race for Gardiner's room. They found it as he said. There was neither sight nor sound of Gardiner.
Sergeant Grey conducted a swift examination, not of Gardiner's room, but of the one in which Allan was lying. He was rewarded by finding the little slip of paper, with a few crystals of powder still clinging to it. The coroner examined the crystals through his magnifying-glass; then, somewhat dubiously, raised them on a moistened finger to his tongue, and after a moment's hesitation swallowed in an impressive, scholarly fashion.
"Saccharum album!" he exclaimed. "Common white sugar! Most extraordinary!"
But Sergeant Grey was at the open window. It was only an eight-foot drop to the soft earth, and to the policeman there was no longer any mystery in Gardiner's disappearance. The mock suicide was a carefully-planned ruse to be employed by Gardiner if the worst came to the worst.
At that moment the sound of horse's hoofs was heard on the gravelly road, and three hundred yards away Gardiner dashed through a gap in the trees that skirted the base of the hills. He was on the policeman's horse, and riding like wild fire.
"I want all of you men, and a horse for each," said Grey, quickly, turning upon them like a general marshalling his officers. "There are a dozen different trails he may fellow, and we must put a man on each. I will give immediate pursuit, in the hope of riding him down before he can throw us off the scent, and I will leave it to you, Mr. Arthurs, to organize the posse and scour the whole country until he is located."
At Grey's first words two men had rushed to the corral, and were already saddling horses. The first and fastest was placed at the command of the policeman, and in a minute he, too, was riding break-neck into the hills. But the delay was enough to give Gardiner almost a mile's lead, and the Government horse was a match for any on the ranch.
Grey knew that the main road, if followed far enough, dwindled into a pack trail, which in turn seemed to lose itself in the fastnesses of the mountains, but in reality opened into a pass leading through the range. He gave Gardiner credit for knowing as much, and concluded that the fugitive would make a bolt straight through the mountains. There was no time to watch for tracks; his chance to ride his man down depended entirely upon speed. If he miscalculated, and Gardiner, instead of making for the pass, sought refuge in the mountains, the posse would certainly locate him or starve him into surrender. So the officer urged his horse to the limit and galloped straight into the mountain battlements ahead of him.
An hour's hard riding brought him into a tremendously rough country, where the trail at times was nothing more than a narrow defile or ledge, and sheer walls of rock rose thousands of feet above, their giant edges cutting the blue sky like the teeth of a mighty saw. Far below, a ribbon of green and white, the river rolled in its canyon. Here and there a thin stream of water sprayed down the mountain side, cutting a damp, treacherous belt across the trail. But at one such spot Grey's heart leaped within him, for there, unmistakably clear in the thin soil and soft rock, were the marks of a horse's shoe, not an hour old. A few minutes later he saw Gardiner swinging round a spur of rock half a mile further up the pass.
The policeman began to watch the moist spots for the tell-tale hoof-prints, and invariably their evidence revealed itself. He knew now that he had guessed Gardiner's course correctly, and it was a matter of minutes until he should ride him down. He wondered whether the man was armed or not; it would be an easy trick to hide behind a rock and pick the policeman off as he rode by.