“There you are!” The Sergeant’s voice instinctively kept to a whisper.  “That’s what you want to see.”

“But I can’t see it—­not so as to get any clear idea.”

No lights showed from the cottage, nor, of course, from the Tower; its only window had been, as Mr. Penrose said, boarded up.  The wind—­there was generally a wind on the heath—­stirred the fir-trees and the bushes into a soft movement and a faint murmur of sound.  A very acute and alert ear might perhaps have caught another sound—­footfalls on the road, a good long way behind them.  The two spies, or scouts, did not hear them; their attention was elsewhere.

“Probably they’re both in bed; it’s quite safe to make our examination,” said the stranger.

“Yes, I s’pose it is.  But look to be ready to douse your glim.  Boomery’s a nailer at turning up unexpected.”  The Sergeant seemed rather nervous.

Mr. Bennett was not.  He took out his torch, and guided by its light (which, however, he took care not to throw towards the cottage windows) he advanced to the garden gate, the Sergeant following, and took a survey of the premises.  It was remarkable that, as the light of the torch beamed out, the faint sound of footfalls on the road behind died away.

“Keep an eye on the windows, and touch my elbow if any light shows.  Don’t speak.”  The stranger was at business—­his business—­now, and his voice became correspondingly businesslike.  “We won’t risk going inside the gate.  I can see from here.”  Indeed he very well could; Tower Cottage stood back no more than twelve or fifteen feet from the road, and the torch was powerful.

For four or five minutes the stranger made his examination.  Then he turned off his torch.  “Looks easy,” he remarked, “but of course there’s the garrison.”  Once more he turned on his light, to look at his watch.  “Can’t stop now, or I shall miss the train, and I don’t want to have to get a bed at Sprotsfield.  A strayed reveler on Christmas night might be too well remembered.  Got an address?”

“Care of Mrs. Willnough, Laundress, Inkston.”

“Right.  Good-night.”  With a quick turn he was off along the road to Sprotsfield.  The Sergeant saw the gleam of his torch once or twice, receding at quite a surprising pace into the distance.  Feeling the wad of notes in his pocket—­perhaps to make sure that the whole episode had not been a dream—­the Sergeant turned back towards Inkston.

After a couple of minutes, a tall figure emerged from the shelter of a high and thick gorse bush just opposite Tower Cottage, on the other side of the road.  Captain Alec Naylor had seen the light of the stranger’s torch, and, after four years in France, he was well skilled in the art of noiseless approach.  But he felt that, for the moment at least, his brain was less agile than his feet.  He had been suddenly wrenched out of one set of thoughts into another profoundly different.  It was his shadow, together with Cynthia