(From the publisher):
For something like two hundred and fifty years Earth had been dominated by humanoid aliens from the star world of Alishang. But man's spirit refused to be conquered. There was a world-wide underground planning for the day of final liberation. And there were four leaders who knew the secret that would guarantee victory - the secret of Zi
Rupert Clinton, intelligence man for this underground, was not one of those four; yet somewhere deep in the recesses of his subconscious mind, he knew Zi's secret.
Original title: The Secret of Zi
Genre: Fiction→ Science Fiction→ Adventure→ Space Opera
Fiction→ Science Fiction→ Alien Beings→ Alien Invasion & Post-occupation
- First published as an Ace Double. The flipside was "Beyond the Vanishing Point" by Ray Cummings.