with
his gang. It was a beautiful plan and it appealed to him in several
ways.

"Those American pigs," he said, "they think through their snouts. They
do not know enough to guard their camp in this country."

But as we know, there was something of a surprise in store for this
enterprising gentleman. It is evident that he was not the same fellow
that Juarez had detected skulking in the woods that morning, for this
was a Mexican who was stalking the boys' camp. He came swiftly through
the grass, with a silence born of custom. It was well for him that he
did, else Jo would have been on his trail in a minute.

The Greaser, for such he deserves to be called, went cautiously up
the slope of the hill, following a small depression which was a
watercourse during the rainstorms. When he got within two-thirds of
the top, he stopped as though he had been struck, for there was the
figure of Jo seated on the rock between him and the fire. For a second
his jaw dropped and his eyes opened wide. Then his cunning ferocity
came to him.

A tall bush and several trees intervened between him and Jo, utterly
unconscious of his danger. Without a sound he crawled along, his
poniard gripped between the gleam of his strong white teeth, which
gave him a snarling and sinister appearance. His plan was evident. He
did not dare to risk a shot, for that would give the alarm and he
would have no chance for loot.

Meanwhile, Jo continued entirely unconscious of the treacherous
approach of this unseen foe. Jo was not thinking of any danger and
his mind was far away on an excursion of its own, dreaming of the far
corners of the earth to which they would sail, if by good fortune
they found the treasure of the Lost Mine.

But Jo was in an ace of taking a longer journey than any that he was
at that moment dreaming of. The Mexican had got almost within striking
distance of Jo and had risen to his feet, not seeing the dog, and was
just drawing back his arm to throw the fatal knife when Shep gave his
growl of warning at the figure he saw in the shadow back of his
master.

If Jo had been careless before he made up for it now. His experience
stood him in good stead, for instead of rising to his feet to confront
the danger as a tenderfoot would have done, he dropped down behind the
rock as quickly as a pugilist ducks his opponent's lead. It was all
that saved him. "Swish" swept the knife with a flash of steel through
the air, where Jo's body had been the