Gradually, as the sullen dawn overcame the blackness of the night, the dreary landscape unfolded itself to the watcher's eyes--an expanse of flat country broken here and there with isolated buildings. Within fifty yards of the barn where the fugitives sheltered was a fairly broad river, that described almost a complete semicircle around the building. "It's running north," soliloquised Billy. "Wonder if it's the Aa? Hanged if I can fix our position with certainty! We've crossed five or six railway lines, and half a dozen small streams. Hang it all! We can't be more than five or six miles from the frontier. By Jove, we are close to the road, though! Wonder if that bridge is guarded?" After a short interval a convoy of motor waggons thundered past. The A.P., roused out of his sleep, sat up. "What's that--an air raid?" he asked drowsily. "No, only traffic," replied Billy. "No cause for alarm. You've another forty minutes yet." A little later on a barge, quite eighty feet in length, manned by a couple of Belgians and towed by a miserably gaunt horse, descended the river. As it rounded the bend the cumbersome craft ran aground. Its stern, being still afloat, was swung round by the force of the wind and jammed against the opposite bank. At the impact, slight though it was, the hatch of the after cabin was thrown back and German soldiers scrambled on deck. One of them was smoking a long pipe with a bent stem. He evidently regarded the situation with philosophical stolidity, but not so his companion. The latter, cursing and reviling the luckless Belgians, danced like a madman on the sodden deck, till, losing his balance, he subsided heavily against the massive tiller. "Bring the horse back, you swine!" he shouted to the man on the bank. "There'll be trouble in store for you if the barge doesn't reach Wuestwezel by noon. Himmel! What will Herr Kapitan say?" Peering through a crack in the door Barcroft watched the proceedings. The German had mentioned Wuestwezel. Consulting the map the flight-sub found that it was a small Belgian village on the frontier, where in pre-war days a customs station was situated. For the best part of an hour the men strove unavailingly to extricate the barge from the tenacious mud. Even the two Huns condescended to assist in the operation but without the desired result. So interested was Barcroft in their frantic efforts that he quite overlooked the fact that it was time for Kirkwood to relieve him. "You'll have to go to Hulstweelde and get additional help, you lazy dogs!" bellowed the infuriated Fritz. Then he said something to his companion, but speaking in a lower tone the words were unintelligible to the young British officer. Apparently there was an argument in progress as to which of the two Germans should accompany the bargees, lest the latter took it into their heads to decamp. Finally all four trudged off, leaving the horse to nibble at the scanty pasture on the bank.