The flight of ships headed south at a speed that heated them white in the air, thin as it was at the hundred mile altitude, yet going higher would have taken unnecessary time, and the white heat meant no discomfort. They reached Antarctica in about ten minutes. The Thessian ships were just entering through great locks in the walls of the dome. At first sight of the terrestrial ships they turned, and shot toward the guard-ships. Their screens were down, for, armored as they were with very heavy relux they expected to be able to overcome the terrestrial thin relux before theirs was seriously impaired.

"Ships will put up screens." Arcot spoke sharply—a new plan had occurred to him. The moleculars of the Thessians struck glowing screens, and no damage was done. "Ships, in order of number, will lower screen for thirty seconds, and concentrate all moleculars on one ship—the leader. Solar investigator will not join in action."

The flagship of the squadron lowered its screen, and a tremendous bombardment of rays struck the leading ship practically in one point. The relux glowed, and the opalescence shifted with bewildering, confusing colors. Then the terrestrial ship's screen was up, before the Thessians could concentrate on the one unprotected ship. Immediately another terrestrial ship opened its screen and bombarded the same ship. Two others followed—and then it was forced to use its screen.

But suddenly a terrestrial ship crashed. Its straining screen had been overworked—and it failed.

Arcot's magnetic beam went into action. The Thessian ray did not go out—it flickered, dimmed, but was apparently as deadly as ever.

"Shielded—write off the magnet, Morey. That is one asset we lose."

Arcot, protected in space, was thinking swiftly. Moleculars—useless. They had to keep their own screens up. Artificial matter—bound in by their own molecular screen! And the magnet had failed them against the protected mechanism of the dome. The ships were not as yet protected, but the dome was.

"Guess the only place we'd be safe is under the ground—way under!" commented Wade dryly.

"Under the ground—Wade, you're a genius!" Arcot gave a shout of joy, and told Wade to take over the ship.

"Take the ship back into normal space, head for the hill over behind the Dome, and drop behind it. It's solid rock, and even their rays will take a moment or so to move it. As soon as you get there, drop to the ground, and turn off the screen. No—here, I'll do it. You just take it there, land on the ground, and shut off the screen. I promise the rest!" Arcot dived for the artificial matter room.