“For fun, indeed!” exclaimed Al Torrance. “People aren’t fooling with the radio ‘for fun’ in these times.”

“I don’t know. You know how girls are,” drawled Whistler. “George, does your sister Lilian know anything about Morse and the radio?”

“Oh, my prophetic soul!” gasped Belding, suddenly arousing to the point Whistler made. “I should say she did! Lil got to be fairly good at both sending and receiving when we had the plant on the roof of our house.”

“Could this be Lilian trying to get a message over to us—just for fun?”

“Cut out the ‘fun’ business,” implored Al. “That doesn’t sound reasonable.” But that was the very idea that caught George Belding.

“She’s that kind of girl,” he declared. “Tell her she must not do a thing, and she’s sure to try it. But I don’t understand——”

“Of course, it’s only a guess on my part,” Whistler said quickly. “But can’t you think of some way to try her out—identify her, you know? Tell Sparks what you think and get him to let you try to send her a message.”

“Whew!” exclaimed Al. “So there’s nothing more than that in it? Shucks! Another mystery gone fooey.”

“Phil’s idea does sound awfully reasonable,” added Belding, evidently much relieved in his mind.

Phil Morgan’s countenance did not reveal his secret gravity. He still remembered that the word “help” had been connected with the names of the two craft—the destroyer and the merchant vessel—which seemed to be a part of the strange message out of the air.