Ick. I don't think that cover moved many units. Review:
One of the worst novels I've read in this Ace Double review series.
The hero is Russell Mason, a "reporter" for the Earth Federation. He has been trained from the age of 6 to be a spaceman, and his particular job is to visit human-colonized planets and report on conditions. . . . Lilith itself is particularly interesting because, get this, it has colors not found in the normal electromagnetic spectrum. Oh.
Mason allows himself to be exposed to a curious manifestation of the light, and he is transformed. He seems to travel in time, and he sees a vision of Man's future, a terrible vision that suggests that humans will be punished by the rest of the intelligent races in the galaxy. Is there something he can do to change things? Then he discovers what sort of research has really been going on on Lilith (weapons research, naturally), and he also discovers other secrets about Lilith and the experimental planets program that disgust him.
And then he goes to the New York Times and blows the lid off the story and all the corruption in the galaxy is over for good and for ever and ever!
I'm just guessing here, but the guys who always loved stories about the Super Intelligent Races of the universe binding together to punish Earth for being naughty were usually the ones who were opposed to long prison terms with manual labor. Odd.