Looking around cautiously, he saw that everything was clear, and dropped down on hands and knees as he reached the gully.  Vladimir was waiting, and in less than a minute explained the secret of the door.

“All right,” said Fred.  “Now you get back to the house, and either be near the entrance to the passage yourself, or keep someone stationed there.  I don’t know what’s going to happen, so I can’t tell you, but I think that maybe I shall get Boris away from the parsonage.”

Vladimir’s eyes gleamed.

“I am an old man,” he said, “and I fear that I am useless.  But if I can help to rescue him—­”

“If you can help, I’ll let you know,” said Fred.  “But I don’t know yet even how I shall set about it.  And I think it’s more important for someone we can trust absolutely to be in the house.  There may be nothing for you to do there, and yet, if anything does come up, you will be needed there very quickly.  Shall you go back through the tunnel?”

“No.  They may have watched me as I came out, and it will be better for them to see me return.  No one suspects the tunnel yet, but some of these Germans are clever.”

“Right!  Well, I know how to get into it now from this end, and that may help a lot.  But I hope that when I use it again Boris will be with me.”

He let old Vladimir go out first.  Then, after waiting for several minutes, he went up the gully in his turn, and set out boldly and with no attempt to hide his movements, for the parsonage.

There was even more activity there now than there had been when he had first set eyes upon it.  There were more automobiles; four of them altogether.  At the wheel of each sat a soldier driver in grey uniform, and with a cloth covered helmet.  Each car was of the same type, a long rakish grey body, low to the ground.  As he neared the house an officer wearing a long, grey coat came out, accompanied by two or three younger men.  He turned to speak to them, then got into one of the cars, which immediately drove off.  As it went a peculiar call was sounded, more like a trumpet than an automobile horn.  Fred guessed then what he afterward learned to be a fact; that the automobiles used by the German staff officers on active service had horns that indicated the rank of the officer using them.

It seemed to Fred that there were more officers than soldiers about.  There seemed to be only enough soldiers to provide a guard.  Sentries were all about, but there were officers almost in swarms.  He walked along, indifferently rather than boldly, and he was sharply challenged when he drew fairly near to the house.

“You can’t go any further, youngster,” said the soldier.  “The staff has taken this house.”

Fred stared at him rather stupidly, but turned away.  Then he was called back suddenly, and for a moment his heart was in his mouth at the thought that his disguise had been penetrated and that he was about to be made a prisoner.  Like Boris, he was concerned only with the effect of this upon his plans.  He did not think of his own safety, although, had he been caught, he might have expected the fate of a spy, since he was in disguise within the German lines.  It proved, however, that he was not to be arrested.  A young captain was eyeing him sharply.