The young woman shook her head. "I have lost my sense of humor," she confessed, adding: "I shall go stark, staring mad if we can't find out something!"
More to keep things from going from bad to worse than for any other reason, Prime suggested a walk in the opposite direction—southward from the breakfast camp. While they were still within sight of the ashes of the breakfast fire they made a discovery. The loose beach sand was tracked back and forth, and in one place there were scorings as if some heavy body had been dragged. Just beyond the footprints there were wheel tracks, beginning abruptly and ending in the same manner a hundred yards farther along. The wheel tracks were parallel but widely separated, ill-defined in the loose sand but easily traceable.
"A wagon?" questioned the young woman.
"No," said Prime soberly; "it was—er—it looks as if it might have been an aeroplane."
II
AMATEUR CASTAWAYS
Lucetta Millington —she had told Prime her name on the tramp to the northward—sat down in the sand, elbows on knees and her chin propped in her hands.
"You say 'aeroplane' as if it suggested something familiar to you, Mr. Prime," she prompted.