“Why should Sparewell pop up here at this time?” pondered Joe. “Do you think he and Hanleigh may be working together?”
“Perhaps. And still, if Sparewell is still alive, I can’t see why this notebook ends where it does. Eleven years have passed since he made these entries.”
“He may have kept other notebooks,” Joe suggested. “Perhaps he merely kept this one because of the cipher. There was some secret he didn’t want others to know, and he kept that notebook in his possession at all times, for fear someone might find it and solve the cipher.”
“That sounds reasonable. But I’m afraid we can’t do much more unless we can learn the secret of that message.”
“It’s a tough one,” Chet commented.
“Ciphers have been solved before this. Have you ever read Edgar Allan Poe’s story called ‘The Gold Bug?’ In that yarn, he had a cipher to solve and he went on the idea that the letter e was the letter most frequently used in the English language,” said Frank. “Suppose we apply it to this case. Looking it over, the letter most often used in the cipher is the letter m. If we take m to mean e—”
“You’ve got it!” shouted Chet. “I’ll bet we’ll solve this riddle yet.”
Frank marked down the letter e above each place in the cipher where the letter m occurred. But he was no farther ahead than he was before. Presuming that m should really be e he found that it occurred once in the first word—for he took it for granted that each dot in the message represented a division between two words—once in the second word, once in the third, once in the fifth and twice in the sixth. This simply rendered the cipher more confusing than ever, for there was no clue as to what the other letters might be.
“If there was a three-letter word in the message,” he said, “we might get somewhere. That’s how the fellow in the story worked it. He found a lot of three-letter words, each of the same combination of letters, so he gathered that they would mean ‘the’ because the letter he thought meant e was at the end of each. That gave him two more letters, t and h, to work on, and from there he found the cipher easy.”
“Mr. Sparewell was too smart for us,” said Joe. “He didn’t use ‘the’ in this message at all, from the looks of things.”
“I guess that scheme isn’t so good. Well, we have the notebook, and whoever lost it is sure to miss it and come back for it. I think it wouldn’t be a bad idea if we kept an eye on that place where the stores were hidden.”
“Catch him in the act!” said Biff.
“If the man is Sparewell, I guess Mr. Jefferson will be mighty glad to know where he is. The police have been searching for the man for fifteen years now. If it isn’t Sparewell, he’ll have a lot of explaining to do concerning this little book and how it came into his hands.”
“From now on, then, we keep a weather eye on those rocks,” Chet declared. “We ought to stand guard.”
“I don’t think that will be necessary,” said Frank. “It would only frighten him away. The best plan is to watch the place from here. We can easily see anyone approaching the island and we can watch to see where he goes. If he heads for those rocks, we’ll know we have our man.”
“That means that someone has to stay on the island all the time.”
“I think it would be best. We can take turns at that, so it shouldn’t spoil our outing. Somehow, I don’t think we’ll have very long to wait. The moment that man finds his notebook is gone, he’ll hurry back for it.”
The other boys agreed that Frank’s plan was about the best that could be devised toward laying the mysterious thief by the heels. They were tingling with excitement because their outing on Cabin Island had plunged them into the depths of a first-rate mystery.
That afternoon they remained on the island. The next day was Christmas and they were preparing to celebrate it accordingly.
But the intruder did not return that day.
XIV
Christmas Day
“I think we ought to make this outing an annual affair,” said Chet Morton the next morning after the boys had wished one another “Merry Christmas.”
“Why?”
“We get two Christmases out of it. It suits me fine.”
“If you expect to get any presents around here, you’re badly mistaken,” sniffed Joe, putting on his shoes.
“I didn’t. If I had expected any I would have hung up my stocking. But we’ll have a Christmas dinner, anyway. That’ll be the second Christmas dinner this week.”
“If we hadn’t found those supplies, you’d be out of luck for your Christmas dinner today. The chicken and the pudding and the Christmas cake were all in those two boxes,” Frank said.
“Didn’t I know it? But everything is all right now.”
“Take a look out the window and see if Hanleigh is snooping around the rocks,” advised Biff.
Chet sped to the window.
“A glorious day!” he reported. “A beautiful, sunshiny Christmas day. The only cloud on the whole horizon is that there is no sign of Mr. Hanleigh. The ice is clear and it looks as if we’ll have some splendid iceboating this afternoon. But Mr. Hanleigh is not iceboating this morning. There is snow on the hillside—but our dear friend Hanleigh is not snowshoeing. But let us not lose hope. He may yet emerge from his hiding place and proceed forth to enjoy the keen Christmas air in the vicinity of Cabin Island, that clear atmosphere that he doesn’t want us
