g the mystery of the
Indians and soldiers whom they had seen the day before.

Laddie had thought up a new riddle--and it was a good one. He knew it
was good and he told everybody about it, he was so excited.

"Listen!" he cried, when he half tumbled out of his saddle by the steps
of the veranda. "This is a good riddle. Listen!"

"We're listening, Son," said Cowboy Jack. "Shoot!"

"What is it," asked Laddie earnestly, "that looks like a horse, has four
legs like a horse, runs like a horse, eats like a horse, but it isn't a
horse?"

"A cow," said his twin promptly.

"No, no! A cow has horns. A horse doesn't," Laddie declared scornfully.

"A colt," guessed Russ.

"No, no!" rejoined the eager Laddie. "A colt is a little horse, so that
could not be the answer, Russ Bunker."

"A giraffe," suggested Vi again.

"I wish you wouldn't, Vi," complained the riddle-maker. "Does a giraffe
look like any horse you ever saw?"

"A carpenter's horse," said Rose.

"Pooh! That's made of wood. Can a wooden horse _run_?" cried Laddie.

"I guess that _is_ a pretty good riddle," said Russ soberly. "What is
the answer, Laddie?"

"Do you all give it up?" asked the smaller boy, his eyes shining.

"You got us thrown and tied," declared Cowboy Jack solemnly. "I couldn't
guess that riddle in a thousand years."

"But you wouldn't want to wait that long to know what it is," Laddie
said delightedly. "Now, would you?"

"You'd better tell us now, Laddie," said Daddy Bunker smilingly. "You
know a thousand years _is_ a long time to wait."

"Well," said the little fellow proudly, "what looks like a horse, and
has four legs like a horse, and runs like a horse, and eats like a
horse, is----"

"Yes, yes!" exclaimed the impatient Violet.

"What is it, Laddie?"

"Why," said Laddie, with vast satisfaction, "it is a _mule_."

They all cried out in surprise at this answer. But it was a good riddle.

"Only," said Russ thoughtfully, "it's lucky you didn't say anything
about its tail and ears. Then we would have caught you."

The Bunker children had so much fun with the ponies Cowboy Jack had
selected for their use during the next two or three days that they
thought of very little else. The mystery of the Indians and soldiers did
not often trouble their minds. But something else did. Mail came from
the East, and with it was a letter from Captain Ben, and another from
Norah.

"And," said Mother Bunker soberly, reading the letters to the ch