“That’s it—how?” Doris laughed uneasily. “He thinks there are many European spies around here!”

“Well—there are!” Mildred nodded her head vigorously.

“You, too?” exclaimed Doris. “But anyhow, Johnny thinks the spies believe we are looking for them—and that they’d do something terrible to us.”

“I shouldn’t wonder,” said Mildred.

“How comforting you are!” Doris smiled ruefully. “Just when I want to feel quiet in my mind! You aren’t helping a bit!”

“Well,” said Mildred, “how can I? There were those men singing in some foreign tongue. They just vanished! And there’s that mysterious, blinking green arrow.”

“Two of them,” Doris corrected. “One on land and one on sea—like Paul Revere!” she chuckled mischievously.

“But of course,” she added more seriously, “there was the man who came on board our boat, sneaking around, and went into a huddle with the octopus! That would have been funny had it not been so terrible. He had a knife that Johnny says no native would carry. But I don’t see—”

“There are a lot of things we don’t see!” Mildred broke in. “For instance—who was that whisperer who was always breaking in when Dave and Johnny in the steel ball were being dragged against the rocks?”

“He might have been a thousand miles away. Radio’s like that,” Doris said, doubtfully.