"Perhaps," replied Rollo. "At all events we'll keep a special eye on the car. One never knows where to expect the unwelcome attentions of those ubiquitous Uhlans, and it will never do to let them pry into the family secrets of our comrades of the 9th." Through the flag-bedecked streets of Brussels the mail convoy made its way. The route, as supplied to the officer in command, was a circuitous one. Proceeding in an almost southerly direction, past the villages of Waterloo, Genappe, and Quatre Bras, the mails for Namur and the left flank of the Belgian field army were to be detached at the village of Sombreffe. The remainder of the convoy was then to proceed through Gembloux to Tirlemont, dropping the crates addressed to various regiments at the nearest points to their ultimate destinations. The motor-cars set out at a rapid pace, so much so that by the time they were clear of the Forest of Soignies, less than ten miles from the capital, the horses and the cyclists were almost "done up". Either speed or the force at the disposal of the convoy had to be sacrificed, and after a hasty consultation with his subordinates, the officer in charge decided upon the latter alternative. Accordingly the lancers were sent back, while a dozen of the cyclists were ordered to leave their machines at a wayside inn and to ride on the cars. From information received from various sources, there was every reason to believe that that part of the country was free from the attentions of the invaders, and no cause to doubt that the mail would be delivered in safety and with celerity. Again the convoy was set in motion, Kenneth and Rollo riding at a distance of about two hundred yards ahead, for their wish to keep an eye on one particular car had been abruptly nipped in the bud. "We've seen the field of Waterloo at all events," shouted Rollo, in order to make himself heard above the noise of the motors. "But it's under different circumstances from those we expected." They had had but a distant and momentary glimpse of the famous pyramid of earth surmounted by the Lion of Belgium. The ground that, less than a century before, was drenched with the blood of men of half a dozen nationalities was again being prepared for a similar object on a vaster scale. Belgian troops and peasants were busily engaged in digging trenches; for here, according to the expectations of military experts, was to be fought the decisive battle that was to save Brussels and Belgium from the Teutonic invasion. At Quatre Bras the convoy struck the Namur road. A couple of miles farther on Kenneth's keen eyes detected a movement towards their left front. In double-quick time the lads dismounted and held up their hands, a signal that brought the convoy to a standstill. "Cavalry, sir!" said Kenneth, pointing in the direction of a clump of trees.