“Listen to this!” called Tom.  “It’s evidently from the diamond makers.”

Holding up the black paper, on which the white writing stood out in bold relief Tom read aloud: 

“Be warned in time!  Go back before it is too late!  You are near to death!  Go back!”

“Bless my shoelaces!” cried Mr. Damon.  “This is getting serious.”

CHAPTER XV—­THE LANDSLIDE

Gathered about the young inventor, the three men looked at the warning.  The writing was poor, and it was evident that an attempt had been made to disguise it.  But there was no misspelling of words, and there were no rudely drawn daggers, or bloody hands or anything of that sort.  In fact, it was a very business-like sort of warning.

“Rather odd,” commented Mr. Jenks.  “Black paper and white ink.”

“White ink is easy enough to make,” stated Mr. Parker.  “I fancy they wanted it as conspicuous as possible.”

“Yes,” agreed Tom, “and this warning, together with the antics of the thing in white last night, shows that they are aware of our presence here, and perhaps know who we are.  We will have to be on our guard.”

“Do you think that fellow Munson, whom we left in the forest, could have gotten here and warned them?” asked Mr. Damon.

“It’s possible,” admitted Tom, “but now let’s see if the person who pinned this warning on our tent took any of our things.”

A hasty examination, however, showed that nothing had been disturbed, and Tom and Mr. Damon were soon getting supper ready, everyone talking, during the progress of the meal, about the events of the day, and the rather weird culmination of it.

“Well, we haven’t had a great deal of success—­so far,” admitted Tom, as they sat about the fire, in the fast gathering dusk.  “I think, perhaps, we’d better try on the other side of the mountain to-morrow.  We’ve explored this side pretty thoroughly.”

“Good idea,” commented Mr. Jenks.  “We’ll do it, and move our camp.  I only hope those fellows don’t find our airship and destroy it.  We’ll have a hard time getting back to civilization again, if we have to walk all the way.”

This contingency caused Tom some uneasiness.  He did not like to think that the unscrupulous men might damage the Red Cloud, that had been built only after hard labor.  But he knew he could accomplish nothing by worrying, and he tried to dismiss the matter from his mind.

They rather expected to see the thing in white again that night, but it did not appear, and morning came without anything having disturbed their heavy sleep, for they were tired from the day’s tramp.

It took them the greater part of the day to make a circuit of the base of Phantom Mountain in order to get to a place where a sort of trail led upward.

“It’s too late to do anything to-night,” decided Tom, as they set up the tent.  “We’ll rest, and start the first thing in the morning.”