This was something utterly foreign to Frank’s expectation.

To run upon a gang of counterfeiters in this out of the way part of the world was certainly a surprise party.

But the young inventor had learned to take the unexpected with other things in a philosophical manner.

Certainly there could have been no safer part of the world than this for the manufacture of counterfeit coin.

It was easy to evade the officers of the law, and also easy to secrete any quantity of the bogus stuff where it could not be located.

The Steam Horse went ahead at quite a rapid gait.

Beaver Bill’s pony followed on behind at a rapid gallop.

The trained animal would at intervals lift its head and neigh shrilly.

“I tell ye, I’m proud of that leetle hoss,” declared the trapper. “He mayn’t be able to jog quite so fast as yer Steam Hoss, but he knows a heap an’ I kin tell yer he’s bin in many a hot scrimmage with me an’ many a time but fer the leetle chap I’d never hev got through.”

“Indeed!” said Frank. “I should think you would be much attached to him.”

“You bet I am, straunger.”

The face of the country here had the happy virtue of being level, though bare and arid.

There were vast tracts of red clay burned beneath the sun’s rays as hard as adamant.

Then sandy plains were crossed and alkali basins.

At times gnarled pillars of coagulated rock were encountered, making a rival of the Bad Lands.

This showed unmistakably the action of the glacial period. Many strange and wonderful freaks of nature were encountered.

But after a time a long, high-capped range of hills began to show up to the westward.

Suddenly Beaver Bill sprang up and pointed to the hills, shouting:

“Thar, friends, do yer see that break in ther range, a kind of a gateway like?”

It required but a glance to see a deep notch in the range of the hills.

It was indeed like a gateway through the mountain wall.

The sky beyond looked peculiar and hazy in its depths.

“Is that——” began Frank.

“Yas,” interrupted Bill, “thet’s ther entrance to Satan’s Hole.”

“But it looks as if there was open country beyond,” declared Frank.

The trapper shook his head slowly.

“That ain’t so!” he declared. “Ye’ll find that ye’re in a level valley with hills all around ye when ye get in there.”

Frank gazed long and critically at the point in question.

“And you say that Mason and his gang are located there?”

“The best I kin make out.”

“All right,” declared Frank. “We’ll soon find out what kind of a place it is.”

The Steam Horse now was sent forward rapidly.

Beaver Bill’s pony seemed to be getting exhausted.

It was now a question as to what to do. But the trapper solved the question.

“I’ll tell ye what to do,” he declared. “Ye know the way to Satan’s Hole now. Ye kin let me out yer an’ I’ll rest my pony up and be along up ter-morrer.”

“Very well,” agreed Frank. “We shall look for you to-morrow.”

“Yas.”

The Steam Horse was brought to a stop and Beaver Bill left the wagon.

He proceeded to loosen the saddle from his pony’s back and give him freedom.

Fortunately there was a brief space of green grass here, and the little animal was enabled to get a bite.

The Steam Horse went on to the entrance of Death Valley.

Soon a plateau was encountered and crossed, then a plain beyond it, and then the travelers saw the pass before them.

Upon either hand rose mighty walls of rock.

It was like the veritable gateway to a Hades, and in spite of themselves all experienced a queer chill.

But Frank kept on until the Steam Horse was fairly in the pass.

The floor of the pass was of smooth rock as level as a floor.

Beyond, now the treacherous valley was revealed as plain as could be.

It looked like an ordinary sandy desert plain.

That was all.

The uninitiated would never have suspected its treacherous character.

“Golly!” cried Pomp, in surprise. “It don’ look no diffrunt from any oder valley, Marse Frank.”

“That’s so,” agreed Frank. “Neither do I see any signs of human life hereabouts.”

The young inventor was thinking of Mason and his gang.

But Barney had begun to sniff the air, and said:

“Bejabers, it’s a divil av a funny smell loike in the air.”

Both Pomp and Frank now realized this.

It seemed like sulphuretted hydrogen, and thoroughly impregnated the atmosphere. Also, with close scrutiny, they could now see unmistakably the sandy trail of death.

There it led across the desert waste, and objects in the sand might be the victims of the death trail. These were certainly plainly visible.

The adventurers gazed upon the scene with peculiar sensations.

Then a blast of air came out from the valley.

It was a peculiar, withering heat, and caused all to gasp for air.

“It is right!” cried Frank; “this is certainly the Valley of Death.”

“Begorra, I believe yez!” cried Barney. “Shure, it luks enough loike it.”

“Golly! I jes’ reckons nuffin’ wud lib in dar,” agreed Pomp.

This was plain to see.

Not a tree or shrub or flowering plant or blade of grass relieved the arid wastes of the Death Valley.

It was a ghostly, forbidding sight.

Even at that distance with a glass Frank was enabled to see the forms of the victims of the gases strewn along the sandy trail of death.

For a time the travelers gazed upon the scene.

Then Frank aroused himself.

“This will never do!” he cried. “We are losing time here.”

“Dat am a fac’, Marse Frank,” cried Pomp.

“Begorra, yez won’t go ahead will yez?” asked Barney.

“I don’t think we will follow the sandy trail of death,” replied Frank. “But I would like to know where Mason’s den is.”

At this moment a sudden startling sound smote upon the ears of all.

The evening air was very still and calm and sound traveled a good ways.

It was plainly enough the distant beat of horses’ hoofs.

It seemed to come from a point above, and now Frank saw a broad trail winding to the right up the side of the pass.

At the same moment the hoof strokes became plainer and then into sight rode a man of peculiar appearance.

He was tall and dark and wore a gay Mexican suit of silk and velvet with glittering patent leather boots.

He was armed to the teeth and rode a large dark colored horse bedecked with gay trappings.

The animal had been trotting down the trail, but now came to an instant halt pulled upon his haunches by the rider.

It was as if some gay Mexican cavalier had burst upon the scene fresh from sunny Mexico.

The rider sat for a moment like a statue, utterly dumfounded at sight of the Steam Horse.

If his appearance had been a surprise to Frank and the others, the sight of the Steam Horse was a revelation to the unknown.

“Perdito!” he gasped, in a thrilled voice. “Am I dreaming? Is it the devil? St. Michael forbid!”

Frank heard his startled words, and at once showed himself at the dasher of the wagon.

“No, it is not the devil,” he replied, “it is the invention of a human being.”

The Mexican was unable to reply for a moment.

Finally, however, he doffed his sombrero with great gravity and replied;

“Buenos, senor! You have the advantage—I have never seen you before. I am Jose Castrello!”

“And I am Frank Reade, Jr.,” replied Frank. “I come from the East.”

“And I am from Mexico, senor,” replied the Mexican, politely. “I am pleased to greet you.”

“The same,” replied Frank.

“But senor will pardon me. I have never seen a horse made of iron before.”

“You have seen locomotives!”

“Ah, that I have. They are plenty now in Mexico.”

“Well, this is built on the same principle, only in the shape of a horse and designed to go without rails.”

“Si, senor, now I see!” cried the Mexican, spurring his horse nearer; “but it is a wonderful thing.”

“Everybody thinks so!” said Frank, modestly.

“Yet it would be as naught and the senors as well should you enter yonder valley.”

“Ah,” said Frank, “then that is really the death valley!”

“Si, senor!”

“A terrible place!”

“Indeed. Many worthy people have lost their lives in that death trap.”

“There should be a notice warning people of the danger.”

“The senor is right!”

Castrello had now reined his horse up quite near to the wagon.

Frank who was a keen student of human nature was doing his best to size the fellow up.

As far as he could see, he was a gay type of the Mexican sport, fond of cards and wine and women.

He did not seem to be a rascal or a cut-throat in any sense of the term.

But what was he doing in this part of the country?

A sudden thought came to Frank.

He might be, like others, a customer of Mason’s, and have come here for a supply of counterfeit money with which to return to Mexico and defraud his countrymen.

The more Frank weighed this matter, the better satisfied he was of the truth.

But yet he was desirous of making sure of the fact.

How to do this without arousing suspicion was a question.

But the Mexican’s curiosity seemed also to have been aroused, and he asked, in a guarded way:

“Has senor traveled far?”

Frank embraced the opportunity.

“We have traveled from the East,” he replied. “And we have come here to find a certain person, whom you may know.”