In the small hours a shadow disengaged itself from the old mill, cautiously. Then it began to run, and resolved itself into a woman. By little paths, by ditches, by side-tracks, Martha reached home. She panted heavily, her face was white and haggard. When she reached her room she flung herself on her bed, and lay there wide-eyed, dumb, horror-stricken, until the dawn broke.

Jefferson’s Battalion finished a tour in the trenches on the following night. Jefferson marched back to billet with a resolve in his mind. He had happened to notice the windmill moving the night before, as he stood outside Company head-quarters in the trenches. He had heard the shells go over—away back—and had seen the sails move again. The two things connected themselves instantly in his mind. Perhaps he should have reported the matter at once, but Jefferson did not do so. He meant to investigate for himself.

Two days later Jefferson got leave to spend the day in the nearest town. He returned early in the afternoon, put his revolver in the pocket of his British warm coat, and set out for the windmill. He did not know to whom the mill belonged, nor did that trouble him.

An Artillery Brigade had parked near the village that morning. Jefferson got inside the mill without difficulty. It was a creaky, rat-haunted old place, and no one lived within half a mile of it. Poking about, he discovered nothing until his eyes happened to fall on a little medallion stuck between two boards on the floor.

Picking it up, Jefferson recognised it as one of those little “miraculous medals” which he had seen strung on a light chain around Martha’s neck. He frowned thoughtfully, and put it in his pocket.

He hid himself in a corner and waited. He waited so long that he fell asleep. The opening of the little wooden door of the mill roused him with a start. There was a long pause, and then the sound of footsteps coming up the wooden stairway which led to where Jefferson lay. The window in the mill-face reflected the dying glow of a perfect sunset, and the light in the mill was faint. He could hear the hum of a biplane’s engines as it hurried homeward, the day’s work done.

A peaked cap rose above the level of the floor, followed by a stout, rubicund face. A Belgian gendarme.

Jefferson fingered his revolver, and waited. The gendarme looked around, grunted, and disappeared down the steps again, closing the door that led into the mill with a bang. Jefferson sat up and rubbed his head.

He did not quite understand.

Perhaps ten minutes had passed when for the third time that night the door below was opened softly, closed as softly, and some one hurried up the steps.