One sharp tug of the twine.  That was the signal to Boris to go ahead.  His eyes strained on the window, Fred saw his cousin’s figure appear on the sill, saw him climbing swiftly up a water pipe, and then saw him drop to the flat roof, hidden for the moment by a low parapet.  Then there was another period of agonized waiting, for again a sentry was to pass.  Fred used the brief interval of enforced inaction to loosen the rope and place it on the ground, tied to the loose end of the twine he took from his wrist, so that it would have a clear passage through the bushes.  Then the coast was clear again, and he signalled to Boris to draw it up.  Up, up went the twine; then the rope started.  And at last it dangled against the side of the house.  Fred, knowing it was there, could scarcely see it himself.  He decided that the sentries would never notice it.

Then came the last pause.  And when the sentry had passed the rope, Boris slipped over the parapet and started his descent.  He had to come quickly for he had less than two minutes to reach the ground and join Fred in his shelter.  Down he came, hand over hand, so fast at the end, when he just slid, letting the rope slip through his fingers, that he must have burned the skin from his palms.  But he made it, and came running toward Fred. He was crouched low against the ground.  But, just before he reached the bushes there was a shout from above, a flash, a loud report.  A bullet sang over Fred’s head, and the next moment the garden was alive with rushing, shouting men, ablaze with flashing points of electric light.  They tried to hide in the shrubbery.  But in vain.  At this last moment, when Fred’s plan had seemed sure of success, disaster had come—­for some German officer, going on the roof, had been just in time to see the rope and spoil everything with his chance shot!

CHAPTER X

SENTENCED

Both Fred and Boris recognized at once the hopelessness of flight.  Both thought instinctively of the hollow and the concealed entrance to the tunnel, and both knew that to attempt to use that now would not save them, and would give away a secret that might be supremely important at some future time, either to them or to someone else among those who shared the precious secret.  The grounds were flashing with light in all directions; soldiers called to one another; men ran all around, looking for them.

And yet, hopelessly caught as they were, neither could give up supinely.  Both had the dauntless fighting spirit that must be conquered, that will never give up, not only while hope remains, but while disaster, be it ever so certain, has not actually come to pass.  They were in a sort of thicket, almost as thick as a primeval jungle.  At the same moment the thought seemed to come to each of them that the one chance for momentary safety lay in keeping perfectly still.  They were side by side, wedged in a little opening they had made for themselves, and now they went down together.