"You're not attached to the 4th army corps, are you? I haven't noticed you among our airmen."
"We are on special service," said Kenneth, feeling that matters were getting warm in spite of the officer's apparent freedom from suspicion. "You'll excuse me, won't you? we are anxious to get to Liége."
"Certainly."
He watched the two men at their work, remarking that it was a very dirty job.
Meanwhile one of the troopers had been edging his horse close to the aeroplane. Pariset, out of the corner of his eye, noticed him looking at it critically. He bent down to examine one of the planes, gave a grunt of satisfaction, and glanced at his officer, as if wondering whether he might venture to address him directly. Concluding that this might be a breach of discipline, he backed gently towards the Wachtmeister--the sergeant-major through whom he might communicate with the lieutenant without being snubbed.
This by-play escaped the notice of Kenneth, who was half-turned towards the lieutenant. That officer, having satisfied his curiosity about the nature of sparking plugs, bade him good-bye, saluted, and gave the order to ride on. The patrol moved away before the trooper had finished his communication to the Wachtmeister.
As soon as they were out of earshot, Pariset whispered:
"One of those fellows suspects something. If they ride back before we have got these plugs in place we must bolt into the wood."
While speaking he kept his eye on the Uhlans without rising from his stooping posture. They were only a hundred yards away when the Wachtmeister rode alongside the lieutenant and spoke to him. The officer gave the order to halt, reined up, and wheeled his horse.
"Get your revolver ready," whispered Pariset.