Scudder was content to call them collectively the 'Black Stone'.

They represented not our Allies, but our deadly foes; and the information, destined for France, was to be diverted to their pockets.

And it was to be used, remember--used a week or two later, with great guns and swift torpedoes, suddenly in the darkness of a summer night.
This was the story I had been deciphering in a back room of a country inn, overlooking a cabbage garden.

This was the story that hummed in my brain as I swung in the big touring-car from glen to glen.
My first impulse had been to write a letter to the Prime Minister, but a little reflection convinced me that that would be useless.

Who would believe my tale?
I must show a sign, some token in proof, and Heaven knew what that could be.