The young man watched his chief for several moments.  Thomson was standing before the window, the cold spring light falling full upon his face, with its nervous lines and strongly-cut, immobile features.  He felt a curious indisposition to speak, a queer sort of desire to wait on the chance of hearing more.

“A single kink in my brain,” Thomson continued, “a secret weakness, perhaps even a dash of lunacy, and I might be quite reasonably the master-spy of the world.  I was in Berlin six weeks ago, Ambrose.  There wasn’t a soul who ever knew it.  I made no report, on purpose.”

“Perhaps they knew and said nothing,” Ambrose suggested softly.

There was a moment’s silence.  Thomson seemed to be considering the idea with strange intensity.  Then he shook his head.

“I think not,” he decided.  “When the history of this war is written, Ambrose, with flamboyant phrases and copious rhetoric, there will be unwritten chapters, more dramatic, having really more direct effect upon the final issue than even the great battles which have seemed the dominant factors.  Sit tight here, Ambrose, and wait.  I may be going over to Boulogne at any hour.”

Thomson pushed on one side the curtains which concealed an inner room, and passed through.  In a quarter of an hour he reappeared, dressed in uniform.  His tone, his bearing, his whole manner were changed.  He walked with a springier step, he carried a little cane and he was whistling softly to himself.

“I am going to one or two places in the Tottenham Court Road, by appointment,” he announced, “to inspect some new patterns of camp bedsteads.  You can tell them, if they ring up from Whitehall, that I’ll report myself later in the evening.”

Curiously enough, the other man, too had changed as though in sympathetic deference to his superior officer.  He had become simply the obedient and assiduous secretary.

“Very good, sir,” he said smoothly.  “I’ll do my best to finish the specifications before you return.”

CHAPTER V

Lord Romsey, after his luncheon-party, spent an hour at his official residence in Whitehall and made two other calls on his way home.  His secretary met him in the spacious hall of his house in Portland Square, a few moments after he had resigned his coat and hat to the footman.

“There is a gentleman here to see you who says that he made an appointment by telephone, sir,” he announced.  “His name is Sidney—­the Reverend Horatio Sidney, he calls himself.”

Lord Romsey stood for a moment without reply.  His lips had come together in a hard, unpleasant line.  It was obvious that this was by no means a welcome visitor.

“I gave no appointment, Ainsley,” he remarked.  “I simply said that I would see the gentleman when he arrived in England.  You had better bring him to my study,” he continued, “and be careful that no one interrupts us.”