s Brayton and I have known each other almost since
childhood. When I was in Yale----"

"You a college man!" exclaimed Tad in surprise.

"Yes. We were engaged. My people were quite wealthy; but, in a panic,
some years ago, father lost everything, dying soon after. Miss Brayton's
family then refused their consent to our marriage. I determined to seek
my fortune in the growing West. My full name is Robert Stallings
Hamilton, though I never had used the middle name until I adopted it
when I became a cowboy. But to return to Miss Brayton. Ruth was taken to
Europe, and then sent to her uncle here. Her trouble preyed on her mind
to such an extent that she grew 'queer.' She had heard that I was a
cattle man, somewhere in the West. Strangely enough, when in her moods,
she developed a strong antipathy to herds of cattle. Whenever a herd was
near, Ruth would slip from the house and steal away to them in the
night, A stampede usually followed. It's a wonder she wasn't shot.
Whether or not she caused these intentionally, Ruth does not know----"

"And that is the mystery?" asked Tad.

"Yes."

"It is the strangest story I ever heard," said the boy quietly.

"What I was about to say, is that the herd will go on without me.
Colonel McClure is sending his own foreman through with it instead. Ruth
and I are to be married at once, and we shall go to my little ranch in
Montana."

In view of the fact that Stallings was severing his connection with the
herd, Professor Zepplin decided to do likewise.

Next morning, at sunrise, Bob Stallings, with Miss Ruth, by his side,
both radiantly happy, rode out to the camp. The Pony Rider Boys had
packed their kits and loaded their belongings on their ponies.
Regretfully they bade good-bye to the cowmen.

Tad's parting with Big-foot was most trying. In the short time they had
been together, a strong affection had grown up between the two. The
plainsman had been quick to perceive Tad's manly qualities, and the boy,
in his turn, had been won by the big, generous nature of the man. They
parted, each vowing that they must see each other again.

As the great herd moved slowly northward, three cheers were proposed for
Bob Stallings and Miss Brayton. This the cowboys gave with a will,
adding a tiger for the Pony Rider Boys.

The trail wagon, pulling out at the same time, held a grinning Chinaman,
huddled in the rear.

"Good-bye, Pong!" shouted the lads.

"Allee samee," chuckled the cook, shaking