of your Department, sent by you, with authority from myself.'
'Well, Mr. Munro,' replied the professor, in that quiet, matter-of-fact way of his, 'this is the first I've ever heard of any Mr. Hale. He certainly has never been sent by us. In fact I was entirely unaware, until this moment, that you had any experiments in progress.'
'Really, professor, I'm awfully sorry to trouble you,' I said. 'But I'm only trying to do my little bit—my very small bit in the war. Thank you for telling me this. One never knows when one meets enemies. The Germans are so clever, so practical, and so subtle.'
'They are,' he answered. 'Be wary, my dear Munro. If you are carrying out experiments upon any extensive scale you may be quite certain that somebody in enemy pay is watching. I have long seen it—long before the outbreak of war.'
Here again we had come up against the dead wall of fact.
'Then you think that the stranger was an enemy spy!' I asked.
'Well, in face of the facts, and of what I myself know, I'm perfectly certain of it,' the professor said. 'I have no knowledge whatever of any person called Harold Hale. He evidently went out to Willesden to try and obtain certain knowledge, yet, by the sturdy attitude of the foreman whom you mention, he was defeated. Truly the wily and dastardly plots of our dear-brother-Germans—as they were called by some irresponsible Englishmen those hot August days of the declaration of war—have been
