The silence that had fallen upon the party was broken by an exclamation from Chris.
"Golly, dar dey is," he cried.
Far off in the direction of the chief's island, a tiny shaft of light pierced the darkness.
"They are on the island we left," exclaimed Charley, "that's their camp-fire."
"No, no," said Walter. "See, it is getting bigger, I bet they have fired the wigwam."
In a few minutes all the party agreed with Walter, there was no mistaking the cause of the pillar of flame that rose high in the air on the distant island.
They watched it in silence until it died down and nothing remained but a faint glare.
"Let's go to bed," said Charley at last. "If they are on the chief's island, they will not bother us to-night."
But after a short discussion, it was decided to stand guard and watch, Charley and Walter to stand on guard until midnight, and then to be relieved by Chris and the captain.
The two sentinels climbed up on a portion of the wall that lay in the shadow of a big tree and from which they could command a good view of the rest of the wall and inclosure itself.