"I wonder how the rascal became acquainted with Judson?" pondered Billy.
"Mixed up with him in some crooked deal or other before this," said Noddy.
They began to walk back to the hotel. They did not enter the lobby by the main entrance, for the path they followed had brought them to a side door. They were glad of this, for, screened by some palms, they saw, bending intently over the register, the forms of the three individuals whose conversation they had overheard.
"Now that you boys know the nature of the work I have been engaged on, I may as well tell you that confidential reports from Washington have warned me to be on my guard," said Captain Simms. "It was in reply to one of these that I sent a code dispatch to-night."
It was half an hour later, and they were all seated in the Captain's room, having told their story.
"But I should have imagined making up a code was a very simple matter," said Billy.
"That is just where you are wrong, my boy," smiled Captain Simms. "A commercial code, perhaps, can be jumbled together in any sort of fashion, but a practical naval code is a different matter. Besides dealing in technicalities it must be absolutely invulnerable to even the cleverest reader of puzzles. The new code was necessitated by the fact that secret agents discovered that an expert in the employ of a foreign power had succeeded in solving a part of our old one. It was only a very small part, but in case of trouble with that country it might have meant defeat if the enemy knew even a fragment of the wireless code that was being flashed through the air."
"Have you nearly completed your work?" asked Jack.
"Almost," was the reply, "but the fact that these men are here rather complicates matters. At Musky Bay, the name of the little settlement where I am stopping, they think I am just a city man up for the fishing. I do not use my right name there. By an inadvertence, I suppose it was habit, I wrote it on the hotel register to-night. That was a sad blunder, for it is practically certain that these men will not rest till they have found out where I am working."
"At any rate I'm mighty glad we followed that Jarrow," said Jack.
"And caught enough of their plans to put you on guard," chimed in Billy.