a low voice, "this letter was sent by
private hands, and by people who were coming to the spot where his
property is, and, of course, it would not do to say anything that would
give any hint of the treasure here. When he writes by mail, he can speak
more plainly."

"I hope he may speak more plainly in another way," said Mrs. Cliff. "And
now let us go up and get our things together. I am a good deal more
amazed by the letter than I was by the ship."

CHAPTER XIX

LEFT BEHIND

"Ralph," said Edna, as they were hurrying up to the caves, "you must do
everything you can to keep those sailors from wandering into the lake
basin. They are very different from the negroes, and will want to explore
every part of it."

"Oh, I have thought of all that," said Ralph, "and I am now going to run
ahead and smash the lantern. They won't be so likely to go poking around
in the dark."

"But they may have candles or matches," said Edna. "We must try to keep
them out of the big cave."

Ralph did not stop to answer, but ran as fast as his legs would carry him
to the plateau. The rest of the party followed, Edna first, then the
negroes, and after them Mrs. Cliff, who could not imagine why Edna should
be in such a hurry. The sailors, having secured their boat, came
straggling after the rest.

When Edna reached the entrance to the caves, she was met by her brother,
so much out of breath that he could hardly speak.

"You needn't go to your room to get your things," he exclaimed. "I have
gathered them all up, your bag, too, and I have tumbled them over the
wall in the entrance back here. You must get over as quick as you can.
That will be your room now, and I will tell the sailors, if they go
poking around, that you are in there getting ready to leave, and then, of
course, they can't pass along the passage."

"That is a fine idea," said Edna, as she followed him. "You are getting
very sharp-witted, Ralph."

"Now, then," said he, as he helped her over the wall, "take just as long
as you can to get your things ready."

"It can't take me very long," said Edna. "I have no clothes to change,
and only a few things to put in my bag. I don't believe you have got them
all, anyway."

"But you must make it take a long time," said he. "You must not get
through until every sailor has gone. You and I must be the last ones to
leave the caves."

"All right," said Edna, as she disappeared behind the wall.

When Mrs. Cliff arrived, she wa