Old Earth

Old Earth isn't just the planet that people left to come to Underhill and its star. Old Earth is the when that the Changed left for when it became evident that the gene-bombs and damaged remnants of the labs of the scientists were still affecting the planet, and that things weren't getting any better. Since most of the Changed were young, and stuck inside the Lay Lines, they didn't have the experience or knowledge to survive the ravages of Underhill as it once was or as it was now. Neither did they have the knowledge necessary to go back through the Gate to Earth. And those who had hidden deep in the mountains, outside the Lay Lines wanted nothing to do with the Changed if they could at all help it.

Somehow, through means lost to time and not recorded, the secrets of small gates were discovered. And once they learned that small gates could be aimed to particular places, such as up to the abandoned space ships left in orbit over the planet. Once there, they managed to get into the data banks. Being young, and never having seen Earth, when they found images of the planet covered in life, safe enough for people not to have to wrap entire islands in anti-grav, and not ravaged by war, they decided to go back.

It wasn't intentional, but they were working off images of a when in Earth's time from before industry and giant cities lay scattered over the planet. Before it grew so crowded that people went to space. Before the soil was used up trying to feed everyone. So when they set their gate anchors for the Earth they saw in those pictures, they not only made it to the home planet, they overshot and made it to the home planet as it was thousands of years before spaceflight was more than a mad dream, and the best the locals would come up with for a long time would be wings of wax and feather.

They went back, and unwittingly bought themselves hundreds upon hundreds of years to adapt to their new and changing bodies, and to develop better relations with those in the mountains.

And to become enmeshed in human legend.