The sight of it was an electric shock. Throwing himself from his horse, he knelt over it in the storm, oblivious for an instant of everything but that this tracery meant her presence, where he now bent, hardly half an hour before. He swung, after a moment's keen scrutiny, into his saddle, with fresh resolve. Pressed by the rising fury of the wind, the wayfarers had become from this point, de Spain saw too plainly, hardly more than fugitives. Good ground to the left, where their hope of safety lay, had been overlooked. Their tracks wandered on the open desert like those who, losing courage, lose their course in the confusion and fear of the impending peril. And with this increasing uncertainty in their direction vanished de Spain's last hopes of tracking them. The wind swept the desert now as a hurricane sweeps the open sea, snatching the fallen snow from the face of the earth as the sea-gale, flattening the face of the waters, rips the foam from the frantic waves to drive it in wild, scudding fragments across them. De Spain, urging his horse forward, unbuckled his rifle holster, threw away the scabbard, and holding the weapon up in one hand, fired shot after shot at measured intervals to attract the attention of the two he sought. He exhausted his rifle ammunition without eliciting any answer. The wind drove with a roar against which even a rifle report could hardly carry, and the snow swept down the Sinks in a mad blast. Flakes torn by the fury of the gale were stiffened by the bitter wind into powdered ice that stung horse and rider. Casting away the useless carbine, and pressing his horse to the limit of her strength and endurance, the unyielding pursuer rode in great coiling circles into the storm, to cut in, if possible, ahead of its victims, firing shot upon shot from his revolver, and putting his ear intently against the wind for the faint hope of an answer. Suddenly the Lady stumbled and, as he cruelly reined her, slid helpless and scrambling along the face of a flat rock. De Spain, leaping from her back, steadied her trembling and looked underfoot. The mare had struck the rock of the upper lava bed. Drawing his revolver, he fired signal shots from where he stood. It could not be far, he knew, from the junction of the two great desert trails--the Calabasas road and the Gap road. He felt sure Nan could not have got much north of this, for he had ridden in desperation to get abreast of or beyond her, and if she were south, where, he asked, in the name of God, could she be?