Out of the infinite depths of interstellar space, a new planet moved in towards the sun... and stayed, between Earth and Venus. Xenephrene, as it was named, made a pretty vision in the evening sky -- until flying things and strange visitants appeared. Xenephrene was inhabited... and it's inhabitants had discovered earth. But who, or what, were these aliens? Were they friends? Invaders? All the Earth would soon know. (from the back cover of an Ace Books later printing)
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