“It’s getting rather lonely here, and there are a couple of vacant hollows in front of us,” remarked the doctor.  “Suppose we move over to one of those, a little nearer the soldiers?”

Patsy approved the proposition, so they gathered up their supplies and moved along the hollow to where a passage had been cut through.  They had gone barely a hundred yards when a screech, like a buzz-saw when it strikes a nail, sounded overhead.  Looking up they saw a black disk hurtling through the air, to drop almost where they had been standing a moment before.  There was a terrific explosion that sent debris to their very feet.

“After this we’ll be careful how we expose ourselves,” said the doctor gravely.  “They have got our range in a hurry.  Here comes another; we’d better get away quickly.”

They progressed perhaps half a mile, without coming upon any soldiers, when at the brow of a hill slightly higher than the rest, they became aware of unwonted activity.  A trench had been dug along the ridge, with great pits here and there to serve as bomb-proof shelters.  Every time a head projected above the ridge, a storm of bullets showed that the enemy was well within rifle range.  In fact, it was to dislodge the Germans that the present intrenchments were being made; machine guns would be mounted as soon as positions had been prepared.

The German bullets had already taken their toll.  In the little valley a poor Belgian pressed his hand against a bad wound in his side, while another was nursing an arm roughly bandaged by his fellows in the trenches.  First aid made the two comfortable for the time being at least and the men were directed toward the ambulance.  As they left, the man with the wounded arm pointed down the narrow valley to where a deep ravine cut through.  “We were driven from there,” he said.  “The big guns dropped shells on us and killed many; there are many wounded beyond—­but you cannot cross the ravine.  We lost ten in doing it.”

Nevertheless, the doctor and Patsy strode off.  Just within the shelter of the ridge they found another Belgian, desperately wounded, and the doctor stopped to ease his pain with the hypodermic needle.  Patsy looked across the narrow defile; it was a bare fifty feet, and seemed safe enough.  Her Red Cross uniform would protect her, she reasoned, and boldly enough she stepped out into the open.  A cry from a wounded soldier ahead hastened her footsteps.  Without heeding the warning shout of Doctor Gys she calmly stooped over the man who had called to her.

And then there was a sudden rending, blinding, terrifying crash that sent the world into a thousand shrieking echoes.  A huge shell had fallen not fifty feet away, plowing its way through the earthworks above.  Its explosion sent timbers, abandoned gun-carriages, everything, flying through the air.  And one great piece of wood caught Patsy a glancing blow on the back of her head as she crouched over the wounded Belgian.  With a weak cry she toppled over, not unconscious, but unable to raise herself.