A half-hour later, the three comrades were two miles across the city from the spaceport, having threaded devious ways to avoid the omnipresent spy-plates of the police.

"Spy-plates” were televisor eyes mounted throughout the city, some openly but many more cunningly concealed, by which police headquarters could keep watch on all parts of the metropolis.

The Planeteers entered the deep shadow of tall trees that bordered extensive grounds. Through the trees glimmered the lighted windows of a magnificent metal mansion. The three comrades moved soundlessly as phantoms toward it.

The mansion was the official residence of the Chairman of the Earth Government. It was on a scale commensurate with the dignity of the elected executive of the planet. The huge tower that housed the Earth Government itself soared into the starlight from a great park nearby.

The Planeteers met no guards as they slipped cautiously toward the rear of the impressive mansion. There was a broad terrace here, splashed with blue-white light from a single window. John Thorn and his comrades stole up onto the terrace toward that window.

Thorn peered tautly into the lighted room. It was a small, paneled study. The only furniture was a big desk which lay in the blue-white pool of a krypton lamp. A gray-haired man sat at this desk, writing.

"It's the Chairman,” Thorn whispered. “And he's alone."

"Good,” muttered Gunner Welk. “That makes it easier!"

Thorn gently reached and pushed on the window. It was unlocked, and swung inward on soundless hinges. He stepped silently in upon the soft rug, and Sual Av and Gunner Welk followed as noiselessly.

The man at the desk suddenly looked up. His haggard, aging face stiffened as he beheld, ten feet from him, the three silent men — the lean, browned young Earthman, the bald, bow-legged Venusian, and the towering, hard-faced Mercurian.