Then to his ears came the voice that had alarmed the Cassells and their tool.

“Roy!  Jimsy!  Are you there?”

“It’s Peggy!” gasped Jimsy.

“And Jess,” he added the next instant, and simultaneously there came the pounding of a stick on the door.

“This is an officer of the law.  Open up at once.”

Jimsy, dazed by his sleep, had not till then noticed the blazing pile of litter.  Now he did so with a quick cry of horror.  The stuff was blazing up fiercely.  Already there was an acrid reek in the air.

“The place is on fire!” he shouted.

The next moment there came a violent assault on the door and the crazy lock parted from its rotten fastenings as a man attired in a police officer’s uniform burst into the place.  Behind him came two wide-eyed frightened girls.  The leaping flames lit up their faces vividly.

“It’s fire sure enough!” cried the police officer.

“Great Scot, what’s happening?”

It was Roy who shouted the question.  He was peering down from the loft where he had been sleeping.  The uproar had awakened him and in a jiffy he was among them.

“Quick! the fire extinguishers!” he cried, and Jimsy, readily understanding, secured the flame-killing apparatus from the biplane and from the Red Dragon.

He and Roy, aided by the officer, fought the flames vigorously, and, luckily, were able to subdue them, though if it had not been for the as yet unexplained arrival of Peggy and Jess it is doubtful if they could have coped with the blaze.  When it was all out Peggy rushed into explanations.

“Something warned me that you were in danger,” she exclaimed, “and I woke up Jess and we found this officer and came down here.”

“What gift of second sight have you?” demanded Roy, gazing at the smoking, blackened pile that had threatened the destruction of the inflammable premises.

“I don’t know.  Womanly intuition, perhaps.  Oh, Roy!”

The girl burst into a half-hysterical sob and threw her arms about her brother’s neck.

“You arrived in the nick of time, sis,” he said, gently disengaging himself from her clasp, “a little more and—­”

He did not finish the sentence.  There was no need for him to.

“Begorry, the ould place ’ud hev bin a pile of cinders in an hour’s time,” declared the policeman.

It was Jess’s turn to give an hysterical little sob.

Roy turned to Jimsy.

“Did you see anything?  The place is reeking with kerosene.  It was a plot to destroy the aeroplanes and perhaps ourselves.”

“I—­I—­”

Jimsy stammered.  The words seemed to choke up in his throat.  How was he to confess that he had failed in his trust—­had slept while danger threatened?

“Well?”

Roy waited, plainly surprised.  It was not like Jimsy to hesitate and stammer in this way.

At last it came out with a rush.