“I wonder if there really are any spies still among us, Jack?” she exclaimed, as, with her soft little hand in his, they were being whirled along up darkened Regent Street in the direction of Hampstead.

“Alas! I fear there are many,” was her lover’s reply. “Poor Jerrold told me many extraordinary things which showed how cleverly conceived is this whole plot against England.”

“But surely you don’t think that there are really any spies still here. There might have been some before the war, but there can’t be any now.”

“Why not, dearest?” he asked very seriously. He was as deeply in love with her as she was with him. “The Germans, having prepared for war for so many years, have, no doubt, taken good care to establish many thoroughly trustworthy secret agents in our midst. Jerrold often used to declare how certain men, who were regarded as the most honest, true John Bull Englishmen, were actually in the service of the enemy. As an instance, we have the case of Frederic Adolphus Gould, who was arrested at Rochester last April. He was a perfect John Bull: he spoke English without the slightest trace of accent; he hated Germany and all her works, and he was most friendly with many naval officers at Chatham. Yet he was discovered to be a spy, having for years sent reports of all our naval movements to Germany, and in consequence he was sent to penal servitude for six years. In the course of the inquiries it was found that he was a German who had fought in the Franco-German war, and was actually possessed of the inevitable iron cross!”

“Impossible!” cried the girl, in her sweet, musical voice.

“But it’s all on record! The fellow was a dangerously clever spy; and no doubt there are many others of his sort amongst us. Jerrold declared so, and told me how the authorities, dazzled by the glamour of Teuton finance, were, unfortunately, not yet fully awake to the craft and cunning of the enemy and the dangers by which we are beset.”

Then he lapsed into silence.

“Your friend Dr Jerrold took a very keen interest in the spy-peril, didn’t he?”

“Yes, dear. And I frequently helped him in watching and investigating,” was his reply. “In the course of our inquiries we often met with some very strange adventures.”

“Did you ever catch a spy?” she asked, quickly interested, for the subject was one upon which Jack usually avoided speaking.