For the first two miles the road skirted the northern shore of the firth, then ascending a steep hill by means of a series of well-engineered zig-zags, it swept across a bleak upland. For the most part the country on either side consisted of sheep-pasture, rough stone walls taking the place of the hedges so common in the south. Here and there were thick clusters of gorse, growing to a height of nearly six feet. There were also clumps of gaunt pines that swayed mournfully in the stiff breeze.
After a while the road began to descend with a long, easy gradient. Away on his right he could just discern the galvanised iron roofs and tall brick chimneys of the Sauchieblair Munition Works. It was only from this part of the road that any distant view could be obtained of the magazines without climbing any of the surrounding hills. Just beyond this spot was a fairly extensive wood.
"I'll bring up here and have a pipe," thought the sub. "I am in plenty of time, and it's only a few miles to Nedderburn."
Leaving the cycle and side-car, he paced up and down the road, for the air was much too keen to stand still. Then, having assured himself that there was plenty of petrol in the tank—experience had taught him that there are such things as leaking carburetters and petrol pipes—he restarted.
Less than a mile from the outskirts of the little village of Nedderburn he espied a trim figure walking briskly in his direction. It was Doris Greenwood.
Presently Tressidar's fears gripped him.
"Hang it!" he soliloquised. "What possible excuse can I have for coming out here?"
With a motor-cycle travelling at twenty miles an hour there is little time to decide upon any matter, but by the time the sub. slowed down he had framed some sort of excuse which might or might not hold water.
"Hulloa, Doris!" he exclaimed in well-simulated surprise. "Whatever are you doing in this unfrequented road?"
"Merely walking for exercise," she replied.