It was true that the fire of the British artillery had increased heavily during the last few minutes.  It was booming and bellowing now in a deep, thunderous roar, the shells were streaming and rushing overhead, and shrapnel was crashing and hailing and pattering down along the parapet of the forward trench; the heavy boom of big shells bursting somewhere behind the forward line and the roaring explosion of trench mortar bombs about the forward trench set the ground quivering and shaking.  A shell burst close overhead, and involuntarily Macalister glanced up, only to curse himself next moment for missing a chance that his captor offered by a similar momentary lifting of his eyes.  Macalister set his eyes on the other, determined that no such chance should be missed again.

But now, above the thunder of the artillery and of the bursting shells, they could hear the sound of rising rifle-fire.  The officer must have glimpsed the hope in Macalister’s face, and, with an oath, he brought the pistol up level again.

“Do not cheat yourself,” he said.  “You cannot escape.  If a charge comes I shall shoot you first.”

With a sinking heart Macalister saw that his last slender hope was gone.  He could only pray that for the moment no attack was to be launched; but then, just when it seemed that the tide of hope was at its lowest ebb, the fates flung him another chance—­a chance that for the moment looked like no chance; looked, indeed, like a certainty of sudden death.  A soft, whistling hiss sounded in the air above them, a note different from the shrill whine and buzz of bullets, the harsh rush and shriek of the shells.  The next instant a dark object fell with a swoosh and thump in the bottom of the trench, rolled a little and lay still, spitting a jet of fizzing sparks and wreathing smoke.

When a live bomb falls in a narrow trench it is almost certain that everyone in that immediate section will at the worst die suddenly, at the best be badly wounded.  Sometimes a bomb may be picked up and thrown clear before it can burst, but the man who picks it up is throwing away such chance as he has of being only wounded for the smaller chance of having time to pitch the bomb clear.  The first instinct of every man is to remove himself from that particular traverse; the teaching of experience ought to make him throw himself flat on the ground, since by far the greater part of the force and fragments from the explosion clear the ground by a foot or two.  Of the Germans in this particular section of trench some followed one plan, some the other.  Of the two men guarding the prisoner the one who was near the corner of the traverse leapt round it, the other whirled himself round behind Macalister and crouched sheltering behind his body.  Two men near the corner of the other traverse disappeared round it, two more flung themselves violently on their faces, and another leapt into the opening of the communication trench.  The officer, without hesitation, dropped on his face, his head pressed close behind the sandbag on which he had been sitting.