“Don’t go to-night, Petit Père!” There was an imploring intonation in the girl’s flute-like voice.

Haynes crossed over to her rapidly. “Princess, you’re tired out and nervous. Go to bed, won’t you?”

“Yes; but promise me—father, you too, all of you—promise me you won’t any of you let yourselves be alone.”

“My dear child,” said Professor Ravenden, “I’ll give you my word for the party, as I am the occasion of the expedition.”

“I—I suppose I am foolish,” Helga said; “but I have dreamed so persistently of some terrible danger overhanging—floating down like a pall.” With a sudden gesture she caught Haynes’ hand to her cheek. “It hung over you, Petit Père!” she whispered.

“I’ll throw a pebble at your window to let you know I’m back alive and well,” he said gaily. “I’ve never seen you so nervous before, Princess.”

“You’ll hardly need the lantern,” said the girl, walking to the door, and looking up at the splendid moon, sailing in the unflecked sea of the Heavens.

“When you’re looking for foot-prints on the sands of time,” observed Everard, “you need the light that never was on sea or land.”

He dropped back as the exploring party filed out into the night, and fell into step with Professor Ravenden.

“Isn’t it true,” he asked, “that all these flying monsters are extinct?”