“I don’t see how—” Mr. Everdail was thinking, as was Sandy, that with everyone whom they suspected, except the maid Miss Serena had accused, present in that room, the loss of the carefully hidden object must be impossible.

“When did you last see it, wherever you had it?” asked the man from London, cool and practical.

“Just before—the meeting here, sir!”

“It was—where?”

“We left it where Dick had discovered it—in the fuselage of Jeff’s airplane. One of us watched, taking turns, all afternoon. Just before we came in here we made sure it was all right, and Larry, who has the longest reach, pushed it in as far as he could get it and still be able to take it out again.”

“Could that girl, Mimi, have come back?” Jeff wondered.

“Whether she did or not,” the pilot, Tommy Larsen, jumped up, “if the life preserver was safe an hour ago, and gone now, it was taken during that hour. Maybe within the last few——”

“Yes—I think it was in the last few minutes!” Sandy declared. “We didn’t talk about the emeralds being hidden in it until almost the last thing before we went to fetch it here.”

“Let’s search the estate!” urged the pilot.

“Come on, everybody—spread out—” cried Jeff. “We’ll get that-there girl——”