The discovery of the watcher at Willowden was most disconcerting to Gray and his accomplices.

They recognised the stranger as a person who had once kept observation upon them in London two years before, and now saw to their dismay that their headquarters had been discovered.

So that night Gray and Claribut worked hard in frantic haste and dismantled the wireless installation, which they packed in boxes, while Freda eagerly collected her own belongings. Then making sure that they were not still being watched they stowed the boxes in the car, and creeping forth sped rapidly away along the Great North Road.

“I don’t like the look of things?” Gray muttered to Freda, who sat beside him. “We’ve only got away in the nick of time. The police might have been upon us before morning. We’ll have to be extremely careful.”

And then a silence fell between them as they drove through the pelting rain. Once again they had wriggled out of an awkward situation.

At a first-floor window of an ancient half-timbered house in a narrow, dingy street behind the cathedral in quaint old Bayeux, in Normandy, a pretty, fair-haired young girl was silting in the sunshine, her hands lying idly in her lap.

It was noon. The ill-paved street below—a street of sixteenth-century houses with heavy carved woodwork and quaint gables—was deserted, as the great bell of the magnificent old cathedral, built by Odo, the bishop, after the Norman Conquest of Britain, boomed forth the hour of twelve.

The girl did not move or speak. She seldom did, because first, her blue eyes were fixed and sightless, and, secondly, she was always strange of manner.

Jean Nicole, the boot-repairer, and his wife, with whom the girl lived, were honest country folk of Normandy. Both came from Vaubadon, a remote little village on the road to St. Lô. After the war they had moved to Bayeux, when one day they chanced to see an advertisement in the Ouest Éclair, an advertisement inviting a trustworthy married couple to take charge of a young lady who was slightly mentally deficient, and offering a good recompense.

They answered the advertisement, with the result that they were invited to the Hôtel de l’Univers at St. Malo, where the worthy pair were shown up to a private sitting-room wherein sat a well-dressed Englishman and a smartly-attired woman, his wife.