Livid with superstition and fear, Peter obeyed. The box was quickly lifted to the foot of the steps and there set down. Then Peter darted back into the tunnel and Edgar followed, grasping the door as he passed and carrying it along with him.

The peril was tremendous, for at any moment the burning brands which dropped and rolled down the steps with every puff of wind might set light to the box and explode its contents. Knowing this, Edgar strained every nerve to put as much space between himself and the fires as possible. Half the length of the passage was traversed in safety, and then, with the thought of Beatrice in his mind, he called Peter back and raised the door upright so that it nearly closed the tunnel.

"Aid me to hold it thus, Peter. Set all thy weight against it. Perchance we may then keep the flame from penetrating to our charges. I know not much of this powder, but I fear the explosion will be terrible."

For nearly half a minute the two young men waited, holding the massive door in position. Then with a mighty roar and flash the explosion came. The noise was terrific, and the shock made the very earth tremble. The door was blown back flat, dashing the two young men to the ground like straws, and a rush of hot air sped over them like a hurricane. Jumping to their feet the instant it had passed, they lifted the door back into position and held it there, choking and gasping with the thick fumes and smoke of the fiery blast.

For a moment there was a calm, followed by the ominous sound of falling objects as the rocks, flung into the air by the explosion, dropped heavily back to the ground. Then all was still again.

"Prop this in position while we go back and see how fared the lady Beatrice," gasped Edgar. "If all is well with her, I believe we may yet win through to safety."

Back through the passage beneath the moat, now knee-deep in water, the young men pressed. The torch had been blown out by the rush of air, and all was pitchy dark.

"Beatrice! Beatrice!" shouted Edgar loudly.

"Here--I am safe--but in sore distress," came the reply, and with a cry of triumph Edgar sprang to her side.

Half-choked by the smoke and fumes, with torch blown out and knee-deep in water, Beatrice's heart had almost failed her, not knowing how her friends had fared exposed to the nearer shock of the dread explosion. Had they perished, her plight and that of poor Jeannette, whom she bore in her arms, would have been mournful indeed.