Because of the recent cooling, life was not far advanced on Jupiter. Too short a time ago the sphere had been but a blazing mass. Tropical marshes prevailed, crisscrossed by mighty rivers at warmer than blood heat. Giant, hideous fernlike growths crowded one another in an everlasting jungle. And among the distorted trees, from the blanket of soft white fog that hid all from sight, could be heard constantly an ear-splitting chorus of screams and bellows and whistling snarls. It made the blood run cold just to listen--and to speculate on what gigantic but tiny-brained monsters made them. Now and then, when Brand had been flying dangerously low over the surface, a wind had risen strong enough to dispel the fog banks for an instant; and he had caught a flash of Jovian life. Just a flash, for example, of a monstrous lizard-like thing too great to support its own bulk: or a creature all neck and tail, with ridges of scale on its armored hide and a small serpentine head weaving back and forth among the jungle growths. * * * * * Occasionally he had landed--always staying close to the space ship, for Jupiter's gravity made movement a slow and laborious process, and he didn't want to be caught too far from security. At such times he might hear a crashing and splashing and see a reptilian head loom gigantically at him through the fog. Then he would discharge the deadly explosive gun which was Earth's latest weapon, and the creature would crash to the ground. The chorus of hissings and bellowings would increase as he hastened slowly and laboriously back to the ship, indicating that other unseen monsters of the steamy jungle had flocked to tear the dead giant to pieces and bolt it down. Oh, Jupiter was a nice planet! mused Brand. A sweet place--if one happened to be a two-hundred-foot snake or something! He had always thought the entire globe was in that new, raw, marshy state. But he had worked only in one comparatively small area of the northern hemisphere; had never been within thirty thousand miles of the red spot. What might lie in that ominous crimson patch, he could not even guess. However, he reflected, he was soon to find out, though he might never live to tell about it. Shrugging his shoulders, he turned into the fifty story building in which was his modest apartment. There he found, written by the automatic stylus on his radio pad, the message: "Be with you at seven o'clock. Best regards, and I hope you strangle. Dex Harlow." * * * * *