"Yes. I see!" he exclaimed as I opened one. "Those are the detonators, filled with fulminate of mercury."

"Let us pass!" cried both the spies.

"Not before you are searched shall you leave this house!" was the quick reply. "If you resist, I shall fire into one of those boxes of detonators, and blow you to atoms."

"And yourselves also!" remarked Klauber, his face pale as death.

"It will at least prevent our secrets falling into your hands, and at the same time bring the truth home to the British Government!" was my friend's unwavering answer.

Next moment both men made a dash towards the door, but I had drawn my weapon and was upon my guard. There was a flash, followed by a deafening report, as Ray fired at the box, aiming wide on purpose.

Then the two spies, seeing that they had to deal with a man who was a patriot to his heart's core, realised that their game was up.

Sullenly Scholtz put down his weapon, and I searched both men.

From the pocket of the exemplary waiter I drew forth a rough plan, together with some scribbled notes in German, which afterwards proved to be a description of the forts on Inchkeith, while from the pocket of Scholtz I secured the tracing he had stolen from Rosyth.

Then we allowed both the secret agents of the Kaiser to pass out, much to the consternation and alarm of the deaf old Scotchwoman, who had, at their request, posed as the occupier of the cottage, but who, in perfect ignorance of what was in progress, had acted as their housekeeper.