the next night, which happened to be one when there was a very hard
storm, he sent Geoffrey down to the bungalow with the little box
containing the letters. He did not wish him to take the car, as it might
be too conspicuous, but had him go on foot. Geoffrey had found out,
during the summer, that one could get into that place through a door at
the side by working at the hook through the crack with a knife-blade, and
he intended to get into the cottage and conceal the box in some
out-of-the-way hiding-place there.

"But here is where the mystery begins. Geoffrey set off that night, but
has never been seen or heard of since. What has happened to him, we
cannot imagine, unless he was caught and taken a prisoner by some one
concerned in getting those letters. If he had been killed, we would
surely know it. Yet if he were alive, it seems as if we should have heard
from him, somehow. He was a most devoted and faithful and trustworthy
soul, so we are sure that something must have happened to him--that he is
being detained somewhere. Grandfather is quite certain that he is
guarding the secret of that box, somehow, and that it would be best to
wait till he comes back or sends us some word.

"What Grandfather asked me to do was to run out here in the car some day,
and, if there was no one about, to scout around and see if I could
discover any clue to the mystery, without attracting attention. He
supposed, of course, that the beach was by that time entirely deserted. I
came out the very next day, but found to my disgust that the cottage next
door was occupied--by you, as I now know! But I felt it would not be wise
to be seen about here in the daytime, so, without saying anything to
Grandfather (who would be awfully upset if he knew it), I determined to
run out about ten o'clock that night and scout around when you people
would probably be in bed.

"And here is where Ted comes into it! I got here that night as I had
planned, found no one about, and tried the experiment of getting into the
side door, as Grandfather had explained, but I found it very difficult;
in fact, quite impossible--for _me!_ And while I was fussing with it, I
was suddenly startled by a low voice, right behind me, inquiring _very_
politely what I was trying to do! It was Ted, here, who had been out for
a stroll, and happening to catch a glimpse of me at this very peculiar
occupation, and naturally thinking I was a burglar, had come up
unobserved to find out a