“There—­I’ve got the lantern!” exclaimed Blackton.  “There isn’t any danger, not a bit.  Wait a minute and I’ll tell you all about it.”  He lighted the lantern, and in the glow of it Joanne’s and Peggy’s faces were white and startled.  “Why, bless my soul, I didn’t mean to frighten you!” he cried.  “I was just telling you facts.  See, we’re standing on a solid floor—­four feet of packed rock and cement.  The dynamite and black powder are under that.  We’re in a chamber—­a cave—­an artificial cavern.  It’s forty feet deep, twenty wide, and about seven high.”

He held the lantern even with his shoulders and walked deeper into the cavern as he spoke.  The others followed.  They passed a keg on which was a half-burned candle.  Close to the keg was an empty box.  Beyond these things the cavern was empty.

“I thought it was full of powder and dynamite,” apologized Peggy.

“You see, it’s like this,” Blackton began.  “We put the powder and dynamite down there, and pack it over solid with rock and cement.  If we didn’t leave this big air-chamber above it there would be only one explosion, and probably two thirds of the explosive would not fire, and would be lost.  This chamber corrects that.  You heard a dozen explosions last night, and you’ll hear a dozen this afternoon, and the biggest explosion of all is usually the fourth or fifth.  A ‘coyote’ isn’t like an ordinary blast or shot.  It’s a mighty expensive thing, and you see it means a lot of work.  Now, if some one were to touch off those explosives at this minute——­ What’s the matter, Peggy?  Are you cold?  You’re shivering!”

“Ye-e-e-e-s!” chattered Peggy.

Aldous felt Joanne tugging at his hand.

“Let’s take Mrs. Blackton out,” she whispered.  “I’m—­I’m—­afraid she’ll take cold!”

In spite of himself Aldous could not restrain his laughter until they had got through the tunnel.  Out in the sunlight he looked at Joanne, still holding her hand.  She withdrew it, looking at him accusingly.

“Lord bless me!” exclaimed Blackton, who seemed to understand at last.  “There’s no danger—­not a bit!”

“But I’d rather look at it from outside, Paul, dear,” said Mrs. Blackton.

“But—­Peggy—­if it went off now you’d be in just as bad shape out here!”

“I don’t think we’d be quite so messy, really I don’t, dear,” she persisted.

“Lord bless me!” he gasped.

“And they’d probably be able to find something of us,” she added.

“Not a button, Peggy!”

“Then I’m going to move, if you please!” And suiting her action to the word Peggy led the way to the buckboard.  There she paused and took one of her husband’s big hands fondly in both her own.  “It’s perfectly wonderful, Paul—­and I’m proud of you!” she said.  “But, honestly, dear, I can enjoy it so much better at four o’clock this afternoon.”

Smiling, Blackton lifted her into the buckboard.