mmer!"

"Rain?"

"Everything. The whole thing. I'm sorry now that we didn't go back up
the trail, but maybe we'd never got up before we were caught. However,
we're pretty safe down here, unless-----"

"Unless what?" piped Chunky.

"Unless we get wet," answered Nance, though Tad knew that was not what
was in the guide's mind.

Just as they were turning back to the camp there came an explosion that
seemed as if the walls of the Canyon had been rent in twain. Chunky
uttered a yell and leaped straight up into the air. Tad took firm hold
of the fat boy's arm.

"Don't be a fool. That was thunder and lightning. The lightning struck
somewhere in the Canyon. Isn't that it, Dad?"

Nance nodded.

"It's always doing that. It's been plugging away at Dad's Canyon for
millions of years, but the Canyon is doing business at the same old
stand. I hope those pintos are all right up there," added the guide
anxiously.

"Mebby they're struck," suggested Stacy.

"Mebby they are," replied Nance. "Come, we'll be getting back unless
you want to get wet."

A dash of rain followed almost instantly upon the words. The three
started at a trot for the camp. They found the Professor and his two
companions anxiously awaiting their return.

"That was a severe bolt," said the Professor.

"Always sounds louder down here, you know," replied Dad. "Echoes."

"Yes, I understand."

"Is---is it going to rain?" questioned Walter.

"No, it's going to pour," returned Chunky. "You'll need your rubber
boots before long."

"Move that camp fire in further," directed Nance. "It'll be drowned out
in a minute."

This was attended with some difficulty, but in a few minutes they had
the fire burning brightly under the ledge. Then the rain began. It
seemed to be a cloudburst instead of a rain. Lightning was almost
incessant, the reports like the bombardment of a thousand batteries of
artillery, even the rocks trembling and quaking. Chunky's face grew
pale.

"Say, I want to go home," he cried.

"Trot right along. There's nothing to stop ye," answered the guide
sarcastically.

"Afraid?" questioned Ned jeeringly.

"No, I'm not afraid. Just scared stiff, that's all," retorted the fat
boy.

The shelf of rock that sheltered them had now become the base of a
miniature Niagara Falls. The water was pouring over it in tons, making
a roaring sound that made that of the river seem faint and far away.

Jim Nance was plainly worri