CHAPTER XV

  A NIGHT ALARM

  The diamonds were wrapped again in their protective covering of tissuepaper. The girls could hardly take their eyes off them as Mr. Nelson putthem in his pocketbook.

  "Oh, it doesn't seem--real," sighed Betty, with a long breath.

  "No, it _is_ like some fairy story," agreed Mollie. "And to think thebox has been in the house two or three days, and we never knew what atreasure it contained."

  "Because of that secret compartment," suggested Amy. "Wasn't it justwonderful?"

  That same false bottom of the tin box was interesting the boys more,just then, than were the diamonds themselves. Will, Allen, Roy and Henrygathered around the queer jewel casket.

  "There, it's shut!" exclaimed Will, as a click proclaimed that he hadpushed the two folding leaves of sheet iron back into place.

  "You'd never know but that that was the real bottom," said Roy.

  "Let's see if we can open it again," proposed Allen.

  The boys tried, pushing here and there. But the bottom did not fly up asit had done for Betty.

  "Say, what magical charm, or 'Open Sesame,' did you use on this?" askedAllen, after vainly trying. "We can't make it work, Bet."

  "I don't know," she answered. "I just simply jabbed it with the ruler,that's all."

  "Well, then, please 'jab' again," pleaded Will.

  Obligingly Betty took the piece of wood, and began poking about in thebottom of the tin box. For some time she was as unsuccessful as the boyshad been.

  "I don't believe I can do it again," she said, puckering her forehead inan attempt to remember. "Let's see, I sat _this_ way, and I held it_that_ way."

  "Did you have your fingers crossed?" asked Roy, laughing.

  "What had that to do with it?" demanded Betty. But before Roy couldanswer she uttered a cry, for, as she was moving the ruler about on thebottom of the box, there was that sudden click and spring again, and thefalse bottom sprang out of the way, disclosing the place where thediamonds had been.

  "How did you do it Betty?" asked Allen, and then it was seen that theruler had pressed on a tiny plate in the corner of the box, a plate sowell hidden that only the most careful scrutiny revealed it.

  Once it was seen, however, the trick was easy to work. The cover wassnapped into place again, and as soon as the ruler, or for that matter,the tip of one's finger, pressed on the little plate, the hiding placewas disclosed.

  The boys and girls "played" the trick over and over again, until it wasan easy matter to do it.

  "This is more fun than the cipher," said Allen, taking a copy of it fromhis pocket.

  "Going to have another go at it?" asked Will.

  "Yes. It might be a clue to the owner of the diamonds."

  "That's so," agreed the other. "I would like to know to whom theybelong."

  "I suppose diamonds are smuggled once in a while; aren't they?" askedAllen.

  "Indeed they are," Will answered. "That's what Uncle Sam has to guardagainst more than anything else. They are so easy to hide, and itdoesn't take many of them to represent a whole lot of money. But thenthe government has the system down pretty fine, and it isn't often thatanything gets away. You see as soon as any purchase of stones on theother side is made, word is sent to the officials here--that is, anypurchase of any large amount, such as this."

  "Then you don't think those diamonds were smuggled?" asked Allen.

  "Not for a minute!" declared Will. "They're the proceeds of somerobbery, all right. I'm sure of that. Smugglers don't work the game thatway--bury the stuff in the sand. It's a robbery!"

  "Well, perhaps you're right," assented Allen, as he bent over thecipher.

  "I'll have another go at that with you," said Will, as he looked overhis copy.

  But the further efforts of the boys, and the girls, too, to decipher thecode, were unavailing. The queer paper held fast to its mystery, ifindeed mystery it concealed. It did not give it up as had the box withthe secret bottom.

  The day when the diamonds were discovered was an exciting one, and theexcitement had not calmed down when evening came. Mr. Nelson had takencharge of the precious stones, and it had been decided not to sayanything about them, even to the servants in the house.

  "And I don't believe I'd take one to the village jeweler," was theopinion of Betty's father. "As a matter of fact, I don't believe hewould be any better judge of the stones than I am, and he certainlywould talk about them."

  "That's right," Mollie agreed. "The folks here want to know what you hadfor breakfast and what you're going to eat for luncheon and dinner. Isuppose they can't help it."

  "No, the natives haven't much to do," affirmed Betty, "except to talkabout the summer cottagers. But we'll keep quiet about the diamonds, atleast down here."

  "If the natives only knew what we know!" exclaimed Grace. "Think ofhaving dug up buried treasure from the sand!"

  "Poor Old Tin-Back would be heartbroken if he ever heard of it," saidAmy, gently. "All his life he has dreamed of finding treasure, orambergris or something, and here we come along and take it right fromunder his eyes."

  "Poor old man," sighed Betty. "He is a dear, and so honest. He broughtsome crabs to-day, hard ones, for the shedders aren't around yet. And hewas so careful to have every one alive. He held them up for me to seethem wiggle."

  "I can't bear them!" exclaimed Grace, making a wry face.

  "You mean uncooked," observed Mollie. "I notice you take your sharewhen the salad is passed."

  "Oh, well, that's different," Grace returned.

  "What are you going to do with the diamonds?" asked Betty of her father,when they were gathered around the sitting room table, after supper.

  "I haven't fully decided," he said. "I want to make some inquiries inBoston, first, as to whether or not there has been a robbery."

  "That's what I'll do, too," said Will.

  "When are you going to Boston?" asked his sister. "First I heard aboutthat."

  "I'm going up in the morning," her brother answered. "I received word toreport at the office. There's something that needs my attention. Ahem!Uncle Sam can't get along without me, it seems."

  "Nothing like patting yourself on the back," Grace said.

  "Just for that you sha'n't have any of--these!" and Will drew from hispocket a box that unmistakably held candy.

  "Oh, Will. I didn't mean it!" Grace cried. "Of course you're of value tothe government. What are they--those new bitter-sweets?"

  "That's for you to ask, and Amy to know," said Will, as he passed Amythe confections.

  "Oh, thank you!" she said, blushing furiously.

  "Amy Blackford. What I know about you!" mocked Mollie.

  "Oh, I'm going to share them, of course."

  "Oh, of course!" chanted Grace. "How nice."

  "Well, it will keep her still for a while, at least," sighed Will.

  "Whom do you mean?" demanded Mollie, catching him by the ear.

  "Ouch! Let go! I meant my sister--of course. A fellow wouldn't dare talkthat way about anyone but his sister," confessed Will.

  Merrily they discussed the finding of the diamonds, and what dispositionmight be made of them. The strange actions of the men in the boat, too,came in for a share of attention. The girls were quite sure the men hadhidden the box in the sand, though whether or not they knew of thevaluable contents was a question.

  "Well, they'll look in vain for it now," declared Betty. "We have it,"and she glanced at the now empty receptacle.

  "Better put it away," suggested her father. "If the servants see it theymay ask awkward questions."

  "I'll keep it in my room," said Betty.

  "And I'll have another go at this cipher to-morrow," Allen said. "Ihave a new idea for solving it."

  "I thought you were going to take us girls out in the boat to-morrow,"objected Mollie.

  "So I am. But I can be working on this between times."

  "Sorry I can't be with you," Will said.

  "Then you are really
going to run up to Boston?" asked Mr. Nelson.

  "Yes, sir, I have to go, if I want to keep this new position."

  "Well, I'd advise you to do so, then. Go up with me on the express inthe morning."

  "Thank you, I will."

  "And if you hear anything about the diamonds, don't wait to come backand tell us, write--no, telegraph!" urged Betty.

  "It wouldn't be wise to wire," her father objected. "There is no greatrush. I will make some inquiries myself."

  "And where will you leave the diamonds, meanwhile?"

  "Down here, of course. I'm not going to carry them around with me--toovaluable," and Mr. Nelson patted his pocket.

  "I'll take the box to my room, and lock it in my trunk," Betty said.

  The evening wore on. It was one of beautiful moonlight, and the partyof young people went out on the beach to have a marshmallow roast over adrift-wood fire.

  "The sea sparkles--just like diamonds," said Mollie, as they turned togo back to the cottage, when the little frolic had ended.

  "Hush!" cautioned Betty. "Some one might hear you," and she looked outover the bay as though she might catch a glimpse of the rough men in theboat.

  "You have diamonds on the brain," chided Grace.

  The cottage became quiet. Only dim night lights burned. Betty had takento her room the queer box, which had given up part of its secret. Herfather had the diamonds with him.

  It was Grace who gave the alarm. Awakening at she knew not what hour,and feeling the need of a drink of water, she donned a dressing gown andfound her slippers. As she went through the hall to the bathroom, shesaw a dark figure, unmistakably that of a man, gliding down thecorridor. Under his arm was the black box, and in one hand was held atissue paper packet.

  "The diamonds!" screamed Grace, her voice shrilling out in the night."Burglars are after the diamonds!"