“That,” Thomson explained, “is almost a personal matter with me.  Three months ago I spent the night with the Third Army Corps up by Niemen.  I was there on other business, as you may imagine, but there was some hot fighting and I went out to help.  I was attending to some of our fellows and got very near to the German lines.  I became separated from the others a little and was groping about when I heard voices talking German within a few feet of me.  I couldn’t hear what they said but I could just distinguish two figures.  One of them made off towards the German lines.  The other, after standing still for a moment, came in my direction.  I took out my revolver, and to tell you the truth I very nearly fired on sight, for it would have been an exceedingly awkward matter for me to have been taken prisoner just then.  Just as my finger was on the trigger, I became conscious that the man who was approaching was humming ‘Tipperary.’  I flashed my light on his face and saw at once that he was a British officer.  He addressed me quickly in German.  I answered him in English.  I fancied for a moment that he seemed annoyed.  ‘We’d better get out of this,’ he whispered.  ’We’re within a hundred yards of the German trenches and they are bringing searchlights up.’  ’Who were you talking to just now?’ I asked, as we stole along.  ‘No one at all,’ he answered.  I didn’t take the thing seriously for the moment, although it seemed to me queer.  Afterwards I regretted, however, that I hadn’t set myself to discover the meaning of what was apparently a deliberate lie.  The next time I met Granet was at a luncheon party at the Ritz, a few days ago.  I recognised his face at once, although I had only seen it by the flash of my electric lamp.  From that moment I have had my suspicions.”

The General nodded.  He was looking a little grave.

“It’s a hateful thing to believe,” he said, “that any one wearing his Majesty’s uniform could ever play such a dastardly part.  However, on the whole I am rather glad that I passed in that request to the War Office.  Anything more we can do for you, Major?”

Thomson took the hint and departed.  A few minutes later he was in his car and on his way back to Boulogne.

CHAPTER XI

Olive Moreton gave a little start as the long, grey, racing car came noiselessly to a standstill by the side of the kerbstone.  Captain Granet raised his hat and leaned from the driving seat towards her.

“Hope I didn’t frighten you, Miss Moreton?”

“Not at all,” she replied.  “What a perfectly lovely car!”

He assented eagerly.

“Isn’t she!  My uncle’s present to me to pass away the time until I can do some more soldiering.  They only brought it round to me early this morning.  Can I take you anywhere?”

“I was just going to see Geraldine Conyers,” she began.

“Do you know, I guessed that,” he remarked, leaning on one side and opening the door.  “Do let me take you.  I haven’t had a passenger yet.”