he had been in, but before he had finished his injunction Ralph
interrupted him.

"Oh, I have told them that already," said he. "They wanted to know where
I had been, and it did not take a minute to tell them what a splendid
swimmer you are, and how you came over after me without taking as much as
two seconds to think about it. And I let them know, too, that it was a
mighty dangerous thing for you to do. If I had been one of those fellows
who were not used to the water, and who would grab hold of any one who
came to save them, we might both have gone to the bottom together."

The captain smiled grimly. "It is hard to get ahead of a boy," he said
to himself.

It was late that afternoon when Captain Horn, with Ralph and the two
ladies, were standing on the rocks in the inner apartment, trying to
persuade themselves that they were having a cosey cup of tea together,
when suddenly a scrambling sound of footsteps was heard, and Maka dashed
through the two adjoining apartments and appeared before them. Instantly
the captain was on his feet, his gun, which had been lying beside him, in
his hand. Up sprang the others, mute, with surprise and fear on their
faces. Maka, who was in a state of great excitement, and seemed unable to
speak, gasped out the one word, "Gone!"

"What do you mean?" cried the captain.

Maka ran back toward the passage, and pointed inward. Instantly the
captain conjectured what he meant. Mok, the second African, had been
stationed to watch the lake approach, and he had deserted! Now the hot
thought flashed upon the captain that the rascal had been a spy. The