They heard the regular pacing of a sentinel in the drive. Nearer to them, on the top of the wall, they fancied that they heard the clash of a bayonet. Granet dropped his voice to the barest whisper.
“We are close there now. Stretch out your hand, Collins. Can you feel a shelf of rock?”
“It’s just in front of me,” was the stifled answer.
“That’s for the stuff. Down with it.”
For a few moments Collins was busy. Then, with a little gasp, he gripped Granet’s arm. His voice, shaking with nervous repression, was still almost hysterical.
“They’re coming, Granet! My God, they’re coming!”
Both men turned seaward. Far away in the clouds, it seemed, they could hear a faint humming, some new sound, something mechanical in its regular beating, yet with clamorous throatiness of some human force cleaving its way through the resistless air. With every second it grew louder. The men stood clutching one another.
“Have you got the fuse ready? They must hear it in a moment.” Granet muttered.
Collins assented silently. The reverberations became louder and louder. Soon the air was full of echoes. From far away inland dogs were barking, from a farm somewhere the other side of the road they heard the shout of a single voice.
“Now,” Granet whispered.