"A' mean the hair," replied Tam gravely, "not the hair that stands up when yeer petrol tank goes dry nor the hare yeer poachin' ancestors stole from the laird o' the manor, but the hair ye breathe when ye're no' smokin'. An' while A'm away in the morn A' want ye to go to Mr. Brandspeth's servant an' get ma new tunic. A'm going to a pairty at Amiens on Friday, an' A'm no' anxious to be walkin' doon the palm court of the Café St. Pierre in ma auld tunic." "Anyway," said the batman, busily brushing that same "auld" tunic, "you wouldn't be walkin' into the Café St. Pierre." "And why not?" "Because," said the batman triumphantly, "that's one of the cafés reserved for officers only." There was a silence, then: "Are ye sure o' that, Angus?" "Sure, Sergeant--I was in Amiens for three months." Tam said nothing and presently began whistling softly. He walked to his book-shelf, took down a thin, paper-covered volume and sank back on the bed. "That will do, Angus," he said presently; "ca' me at five." The barriers were up all around--they had been erected in the course of a short week. They penned him to his class, confined him to certain narrow roads from whence he might see all that was desirable but forbidden. * * * * * He was so silent the next morning, when he joined the big squadron that was assembling on the flying field, that Blackie did not know he was there. "Where's Tam? Oh, here you are. You know your position in the formation? Right point to cover the right of the American bombing squad. Mr. Sutton before you and Mr. Benson behind. You will get turning signals from me. Altitude twelve thousand--that will be two thousand feet above the bombers--no need to tell you anything. The objective is Bapaume and Achiet junctions--" Tam answered shortly and climbed into his fuselage. The squadron went up in twos, the fighting machines first, the heavier bombing airplanes last. For twenty minutes they maneuvered for position, and presently the leader's machine spluttered little balls of colored lights and the squadron moved eastward--a great diamond-shaped flock, filling the air and the earth with a tremulous roar of sound. They reached their objectives without effective opposition. First, the junction to the north of Bapaume, then the web of sidings at Achiet smoked and flamed under the heavy bombardment. Quick splashes of light where the bombs exploded, great columns of gray smoke mushrooming up to the sky, then feeble licks of flame growing in intensity of brightness where the incendiary bombs, taking hold of stores and hutments, advertised the success of the raid. The squadron swung for home. Tam with one eye for his leader and one for the possible dangers on his flank, was a mere automaton. There was no opportunity for displaying initiative--he was a cog in the wheel.