“That sends the gooseflesh up my spine,” he said.

“Are you scared?” asked Bob.

“I’m scared stiff,” averred Frank.  “My hair is standing up so straight I wonder how my sombrero stays on.”

“Me, too,” said Bob.

“Liar,” said Frank.

“You’re another,” said Bob.  “You’re not scared.  I know you too well.”

They grinned affectionately at each other.  Jack who meantime had been investigating, turned with a worried expression.

“I’ve followed Tom’s directions faithfully,” he said.  “He said to lay our course south by south-west and showed me what he meant on my compass.  I haven’t deviated a hair’s breadth.  Somewhere about here should be the first landmark—­three rocks shaped like a camel lying down.  But I can’t see them.”

“Nothing to worry about in that,” said Frank.  “Probably we haven’t gone far enough.  Let’s push on.”

“That must be it,” said Jack with relief.  “Well, come on.”

Before they could get into motion, however, Bob uttered a warning whisper.

“Listen,” he said.  “I heard a horse stumble behind us on the trail.”

They listened breathlessly a moment, but no further sound was heard.

“Keep your guns handy,” whispered Jack.  Whenever the three were together he took command.  “Don’t fire without cause, however,” he whispered.  “If there is someone behind us, it may be another traveller.”

Again came the sound of a horse stumbling.  All heard it distinctly.  Jack peered into the darkness and called firmly: 

“Who are you?”

“Challenge him in Spanish, why don’t you?” muttered Frank.

Before Jack could repeat his challenge, however, a familiar voice replied: 

“That you, Jack?  This is Tom.”

“Tom?  Tom Bodine?”

“The same,” replied the ex-cowboy, materializing out of the darkness, and approaching.  “And glad I am,” he added, “to find you.”

“But, good gracious, Tom, is anything the matter?  Why are you here?  I thought we left you heading back for home five hours ago?”

“No, you just left me,” said Tom.  “That’s all.  I didn’t head home, because I wanted to come along.  Been a-trailin’ you all the way.  And here I am.”

Jack was surprised, indeed.  But now that Tom was with them, he experienced a sense of relief.  To venture into a strange land without a guide, and in pitch darkness, besides, was a pretty stiff undertaking.  The responsibility of looking after his friends was no light one.

“To tell the truth, Tom,” Jack said, “I’m glad you came.”

Bob and Frank echoed his words heartily.

“I had just about decided when you came up,” Jack added, “that I had lost my way.  Frank thought, however, we merely hadn’t gone far enough to find your landmarks.”

“He was right,” said Tom.  “You come straight as a die.  All we got to do is to ride on a piece an’ we’ll be in the snuggest cave ever you see.”