The strange, bewildering sound filled the room.  And now, as the wind shifted, the steady rattle of musketry became suddenly audible.  Another sound, sinister, ominous, broke on their ears, the clang of the seminary bell.

“Is it an attack on this place?” she asked anxiously.  “What can we do?  There are no troops here!  I—­I must go to my sick boys——­”

Her heart stood still as a cannon thundered, followed by the fearful sound of the shell as it came tearing toward them.  As it neared, the noise grew deafening; the air vibrated with a rushing sound that rose to a shriek.

Ailsa’s hands grasped his arm; her ears seemed bursting with the abominable sound; pain darted through her temples, flashing into agony as a heavy jar shook the house, followed by a dazzling light and roar.

Boom!  Boom! came the distant, sullen thunder, followed by the unmistakable whir of a Parrott shell.  Suddenly shrapnel shells began to come over, screaming, exploding, filling the air with the rush and clatter of bullets.

“Lie down,” he said.  “You can’t go out in this.  It will veer off in a few moments, when they find out that they’re shelling our hospitals.”

“I’ve got to go,” she repeated; “my boys won’t understand why I don’t come.”

She turned and opened the door; he caught her in his arms, and she looked up and kissed him.

“Good-bye, dear,” she whispered.  “You mustn’t detain me——­”

“You shall not go outside——­”

“I’ve got to.  Be reasonable, dear.  My sick are under fire.”

The bugle was sounding now; his arms fell from her waist; she smiled at him, stepped outside, and started to run; and found him keeping pace between her and the west.

“You should not do that!” she panted, striving to pass him, but he kept his body in line with the incoming missiles.  Suddenly he seized her and dropped flat with her as a shell plunged downward, exploding in a white cloud laced with flame through which the humming fragments scattered.

As they rose to their knees in the dust they saw men gathering—­soldiers of all arms, infantry, dismounted cavalrymen, hospital guards, limping convalescents, officers armed’ with rifles, waggon drivers, negroes.

“They’re attacking our works at Cedar Springs,” said an officer wearing one hand in a sling.  “This hospital is in a bad place.”

Ailsa clapped both hands over her ears as a shell blew up at the angle of an outhouse and the ground rocked violently; then, pale but composed, she sprang inside the hospital door and ran for her ward.

It was full of pungent smoke; a Parrott shell had passed through a window, carrying everything away in its path, and had burst, terrifying the sick men lying there, but not injuring anybody.

And now a flare of light and a crash outside marked the descent of another shell.  The confusion and panic among the wounded was terrible; ward-masters, nurses, surgeons, ran hither and thither, striving to quiet the excited patients as shell after shell rushed yelling overhead or exploded with terrific force, raining its whirring iron fragments over roof and chimney.