As a result Bruce was coaxed to Mahan’s company-shed and by dint of food-gifts and petting was induced to spend most of the day there.

At sunset Bruce tired of his dull surroundings.  Mahan had gone on duty; so had Vivier; so had others of his friends.  The dog was bored and lonely.  Also he had eaten much.  And a walk is good, not only for loneliness, but for settling an overfull stomach.  Bruce decided to go for a walk.

Through the irregular street of the village he picked his way, and on toward the open country beyond.  A sentry or two snapped fingers of greeting to him as he strolled past them.  The folk of the village eyed his bulk and graceful dignity with something like awe.

Beyond the hamlet the ridge of hilltop ran on for perhaps a quarter-mile before dipping into the plain below.  At one end of this little plateau a company of infantry was drilling.  Bruce recognized Mahan among the marching lines, but he saw his friend was on duty and refrained from going up to him.

Above, the sunset sky was cloudless.  Like tiny specks, miles to eastward, a few enemy airships circled above the heap of clustered hills which marked the nearest German position.  The torn-up plain, between, seemed barren of life.  So, at first, did the farther end of the jutting ridge on which the village was perched.  But presently Bruce’s idly wandering eye was caught by a flutter of white among some boulders that clumped together on the ridge’s brow farthest from the village.

Some one—­a woman, from the dress—­was apparently picking her way through the boulders.  As Bruce moved forward, a big rock shut her off from his view and from the view of the hamlet and of the maneuvering infantry company a furlong away.

Just then a puff of breeze blew from eastward toward the collie; and it bore to him a faint scent that set his ruff a-bristle and his soft brown eyes ablaze.  To a dog, a scent once smelled is as recognizable again as is the sight of a once-seen face to a human.  Bruce set off at a hand-gallop toward the clump of boulders.

The Red Cross nurse, whom Bruce had so nearly killed, was off duty until the night-shift should go on at the hospital.  The nurse had taken advantage of this brief surcease from toil, by going for a little walk in the cool sunset air, and had carried along a bag of sewing.

Up to three months ago this nurse had been known as Heinrich Stolz, and had been a valued member of the Wilhelmstrasse’s workingforce of secret agents.  Then, acting under orders, Herr Heinrich Stolz had vanished from his accustomed haunts.  Soon thereafter a Red Cross nurse—­Felicia Stuart by name had reported for duty at Paris, having been transferred thither from Italy, and bearing indubitable credentials to that effect.

From carefully picked-up information Stolz had just learned of the expected arrival of the three troop-trains at the junction at nine that evening.  The tidings had interested him keenly, and he knew of other people to whom they would be far more interesting.