The man who holds the lead in an affair of this kind holds the advantage, for the pursuer, if he overhauls the pursued, must inevitably come up to the scratch winded. Jacques had come to the conclusion that the murderer was unarmed, else here, in this desolate place, he would undoubtedly have attacked instead of running away. Believing this, he determined to hang on the other's heels, wear him down, and then close with him. He knew his own powers; a born long-distance runner and trained to feats of almost fabulous endurance by his seven years' life in the Legion, he felt that he held the trump card, and if, as he felt certain now, Mansoor was unarmed, he had no fear of the issue. Sidi-bel-Abbès is situated on the borders of the desert, but the Algerian desert must not be confused with the Sahara, in those places where it shows limitless wastes of sand. The desert places of Algeria show little sand except in districts away down south, as, for instance, by the Oasis of the Five Palms or that great, sandy track where we saw the Legion fronting the Arabs and defeating them. The desert of Algeria consists of waste land, rock-strewn and desolate, yellow earth, sun-baked and hardened, a few miserable scrub bushes and cacti, an occasional oasis with palm trees blowing in the desert wind. There is no water, except that which flows underground and breaks to the surface here and there to form the oasis pools. Through this wilderness runs the great southern military road, built by the soldiers of the Legion, and the line Mansoor was now taking lay to the west of this road. It was his object to avoid the road; in this Jacques was with him; the road meant military patrols and the prize taken out of Jacques' hands. Five hundred francs! Never for a moment had the idea left his mind; it had driven him like a charging bull into the shop of the cigarette-maker, it led him in pursuit down the lane, over the rampart, into the ditch and through the market garden; it was leading him now on the most desperate and dangerous chase that man ever engaged in, and it would lead him to the end, whatever the end might be. The serious fact for Mansoor at that moment lay, not in the fact that he was a murderer, but the fact that he was five hundred francs. He was bundles of Algerian cigarettes, bottles of blue Algerian wine, jolly evenings at the canteen, lots of soap to wash uniforms with, kisses from black-eyed girls, glasses of coloured liqueurs at Kito's--and he was being chased by Jacques!--heaven help him! The half-moon blazing in the sky lit the chase, and the cold of the Algerian night checked the breath of Jacques. It seemed also to affect Mansoor, for all of a sudden he slackened his pace from a jog-trot to a quick walk. His pursuer did the same, nothing loth. At this pace, the marching pace of the Legion, he could keep on all night and half the next day.