His uncle listened with interest, not unmixed with some alarm, interrupting him at times with questions.

“You did well, both of you,” Captain Sturdy said approvingly when Don had finished. “Though it would perhaps, have been more prudent if you had summoned help as soon as you had discovered the state of things before you climbed through the transom. You ran a big chance of having one or both of those rascals stick a knife into you.”

“I suppose so,” answered Don. “But I didn’t think of that. All I saw was that helpless old man in the power of those villains. If they’d only been a minute or two later in getting back, we’d have had the old man out on the deck, and they wouldn’t have dared to attack him there.”

“It’s curious that the thieves should have attempted so bold a thing right here on the ship,” remarked the professor. “They must have been desperately anxious to get what he had. Had they searched his baggage?”

“No,” replied Don. “And that’s the funny thing about it. They hadn’t broken into his bags or trunk, and it didn’t seem that they intended to do so.”

“But you say that they were there to rob him?” said the professor, in some perplexity.

“Yes,” replied Don. “But the thing they wanted to get wasn’t in his baggage. It was in his mind.”

“You mean they wanted to extort a secret from him?” put in the captain.

“That was it,” Don affirmed. “The old Egyptian told us that himself. They were going to torture him to get it out of him.”

“It must have been very valuable if they were prepared to go to such lengths as that,” remarked the professor. “Did he tell you what it was?”