"Perhaps," said Gerrod.

The plane flew on steadily, Davis finding some amusement in gratifying Nita's suddenly aroused curiosity about every part of the seaplane. When her curiosity about the plane was satisfied, however, and she began to make inquiries about himself, Davis was much less comfortable.

He tried to be evasive, but she pinned him down, and was filled with excitement when she found that he was the same man who, as Lieutenant Davis, had flown the two-seated flying machine that had destroyed the Black Flyer and with it Varrhus' menace to the liberty of the world.

She tried very hard indeed to get him to tell her the story of that fight, but he blushed and said there was nothing to tell. It would be hard to say to what lengths she would have gone had not something outside the plane caught her attention.

"There's the horizon!" she exclaimed. "We've come to the edge of the silver sea, and from here on it's just the plain, good, old-fashioned ocean."

The line that marked the point where sea and sky joined was indeed visible, and a gradually widening bank of darker blue showed that the silver sea had indeed come to an end.

As the seaplane flew onward the darker, wave-tossed ocean came toward them and passed below, but blended so gradually with the jellied ocean that it was impossible to tell where the silver sea ended and blue water began. It was evident that the silver sea was still growing.

Then, for a long time, the seaplane sped onward over the blue waters, while Nita tried ingeniously to extract from Davis the details of the fight with the Black Flyer.

Davis was acutely uncomfortable, but nevertheless he felt strangely disappointed when the dim line of the coast appeared ahead. He hovered a moment to get his bearings, and then sped northward toward the aviation station to which he was attached.

Nita, too, seemed disappointed. She had enjoyed tormenting Davis, and he impressed her very favorably. After the plane had swooped downward and come to rest on the water a scant two hundred yards from the hangar in which it was kept, she turned to Davis.