Jack half rose from his chair as if he intended to follow him.

“What’s the trouble?” asked Sam.

“I don’t mean to let Jarrold out of my sight, that’s all,” said Jack. “But look! He has stopped. He is talking to someone. That chap in a sun helmet. I can’t see his face, but somehow he looks mighty familiar to me.”

The young man who had joined Jarrold strolled along the terrace with him till they both found chairs. Then they sat down and seemed to be engaged in earnest conversation. The stranger, who yet seemed familiar to Jack, had his back turned to them so that it was impossible to see his features.

At length they arose, shook hands as if they had come to an agreement on some matter, and parted. Jarrold came into the garden and took a seat at a table. He scowled heavily at the boys as he passed them, but gave no other sign of recognition. Suddenly Jack rose to his feet.

“I’m a fine chump!” he exclaimed. “I ought to have brought my camera along. Hanged if I didn’t forget it!”

“Why don’t you go back to the ship for it?” asked Sam. “It’s not very far. You can get there and back in twenty minutes or less if you drive.”

“That part of it is all right. But I hate to leave His Nibs, there, unwatched.”

“Oh, as for that, I’ll take care of him till you get back,” Sam promised.

“Bully for you! Then I’ll go. And say——”