“Yes, go on.”

“Those papers are pretty valuable, dad said.  There are other parties interested in this deal, and if they got hold of the documents it might make a lot of trouble.”

“Trouble?”

“Yes.  But there’s not much chance of that.  They don’t even know where the papers are.”

“All right, I’ll get them.  Have a good time at the game, Billy boy.”

“I will, and look out for Prince.  So long!” and Will hung up the receiver, while Grace over the private wire, telephoned to the groom to saddle Prince.  Then she went out to tell her friends of her little trip.

And while she is doing this, I will interject a few words of explanation so that those who did not read the first volume of this series may have a better understanding of the characters and location of this story.

The first book was called “The Outdoor Girls of Deepdale; Or, Camping and Tramping for Fun and Health.”  In that is given an account of how the four chums set off to walk about two hundred miles in two weeks, stopping nights at the homes of various friends and relatives on the route.  At the very outset they stumbled on the mystery of a five hundred dollar bill, and it was not until the end that the strange affair was cleared up most unexpectedly.

The four girls were Betty Nelson, a born leader, bright, vigorous and with more than her share of common sense.  She was the daughter of Charles Nelson, a wealthy carpet manufacturer.  Grace Ford, tall, willowly, and exceedingly pretty, was blessed with well-to-do parents.  Mr. Ford being a lawyer of note, who handled many big cases.  Mollie Billette, was just the opposite type from Grace.  Mollie was almost always in action, Grace in repose.  Mollie was dark, Grace fair.  Mollie was quick-tempered—­ Grace very slow to arouse.  Perhaps it was the French blood in Mollie—­ blood that showed even more plainly in her mother, a wealthy widow—­ that accounted for this.  Or perhaps it was the mischievous twins—­ Dodo and Paul—­ whose antics so often annoyed their older sister, that caused Mollie to “flare up” at times.

Amy Stonington was concerned in a mystery that she hoped would some day be unraveled.  For years she had believed that John and Sarah Stonington were her father and mother, but in the first book I related how she was given to understand differently.

It appears that, when she was a baby, Amy lived in a Western city.  There came a flood, and she was picked up on some wreckage.  There was a note pinned to her baby dress—­ or, rather an envelope that had contained a note, and this was addressed to Mrs. Stonington.  Amy’s mother was Mrs. Stonington’s aunt, though the two had not seen each other in many years.

Whether Amy’s parents perished in the flood, as seemed likely, or what became of them, was never known, nor was it known whether there were any other children.  But Mr. Stonington, after the flood, was telegraphed for, and came to get Amy.  He and his wife had kept her ever since, and shortly before this story opens they had told her of the mystery surrounding her.  Of course it was a great shock to poor Amy, but she bore it bravely.  She called Mr. and Mrs. Stonington “uncle” and “aunt” after that.