guess not. Those bandits had the drop on them, and they couldn't have
put up much of a fight. How do you suppose we heard those shots? We must
be at least a mile from the tank.

"Him fog," Injun answered. "Hear plain." And it is true that fog has a
way of conveying sound.

An idea brought Whitey to his feet with a leap. "What fools we are to be
sitting here!" he cried. "We'll follow those robbers. The people on the
train won't do that. They've no horses."

Here, indeed, was a brilliant thought. The boys could track the bandits
to their hiding-place, and possibly recover the ore. At least, they
could return and report where the men had gone. There was a chance to
distinguish themselves yet. In a moment they were mounted and dashing
down along the track, toward the water tank.

Presently a shrill whistle was followed by the faint rumbling of the
train as it resumed its way. "See?" yelled Whitey. "The train's just
starting. We won't be very late, and the men's tracks will be plain.
Gee! I hope it doesn't rain."

A few minutes' ride brought the boys to the deserted water tank. They
dismounted to pick up the trail of the robbers. Near the tank, where the
express car must have stood, were the traces of many feet. There were
others leading from the cars in the rear. Noting these, Whitey said:
"Mebbe they held up the passengers, too. It's likely that they would."

But, singularly enough, most of these tracks led on toward the high
bridge which spanned the gully. The boys followed them curiously, and