The story told of another Earth, in the same orbit as our planet but on the opposite side of the sun, whose scientifically advanced civilization visits us in flying saucers. Comics historian Stephen Donnelly noted: While semi-retired, Lebeck teamed with McWilliams (who had illustrated some of Lebeck's past books and had done work for him at Dell Comics) to launch Twin Earths. It made use of the duplicate earth concept and tapped into the growing interest during the period in Flying saucers. In 1957, Lebeck retired and McWilliams assumed scripting duties for the strip.