“A thunderstorm!” Wade began, but Arcot interrupted.

“Not so fast, Wade—Fuller's animal is there—the only animal in all creation that can make a noise like that! Look through the telescope—see those dots wheeling about there above the flashing lights? The only animal that can make that racket is man! There are men over there—and they aren't in a playful mood! Turn on the invisibility while we can, Morey—and let's get nearer!”

“Look out—here we go!” Morey began to close a tiny switch set in one side of the instrument panel—then, before the relay below could move, he had flipped it back.

“Here, you take it, Arcot—you always think about two steps ahead of me—you're quicker and know the machine better anyway.”

Quickly the two men exchanged places.

“I don't know about that, Morey,” said a voice from vacancy, for Arcot had at once thrown the ship into invisibility. “The longer we're here, the more mistakes I see we made in our calculations. I see what put me off so badly on my estimate of the intelligence of life found here! The sun gives it a double dose of heat—but also a double dose of other radiations—some of which evidently speed up evolution. Anyway, we may be able to find friends here more quickly if we aid one side or the other in the very lively battle going on there. Before we go any further, what's our decision?”

“I think it is a fine idea,” said Fuller. “But which side are we to aid—and what are the sides? We haven't even seen them yet. Let's go nearer and take a good look.”

“Yes—but are we going to join either side after looking?”

“Oh, that's unanimous!” said Wade, excitedly.

The invisible ship darted forward. They sped past the barrier of low hills, and were again high above a broad plain. With a startled gasp, Arcot cut their speed. There, floating high in the air, above a magnificent city, was a machine such as no man had ever before seen! It was a titanic airplane—monstrous, gargantuan, and every other word that denoted immensity. Fully three-quarters of a mile the huge metal wings stretched out in the dull light of the cloudy Venerian day; a machine that seemed to dwarf even the vast city beneath it. The roar of its mighty propellers was a rumbling thunder to the men in the Solarite. From it came the flashing bursts of flame.