Human saboteur sows disorder on enemy alien planet


New Member
May 8, 2016
In the late sixties, I read a SF hardcover in which Earth is at war with a group of alien planets. The human protagonist is dropped (alone) on one of the planets, where he engages in covert sabotage and propaganda warfare. Ultimately his efforts lead to the capture of the planet by Earth forces.

I seem to remember that the aliens looked a lot like humans, so he was able to pass as one of them by dying his skin blue (or was it green?) and by using other disguises.

Funny, I can't remember the title and it's driving me crazy! I thought the word "Blue" was in the title, but I haven't been able to find anything like it.