Out of Phaze by Piers Anthony

the Herd, and they would recognize him with or without clothing, and bear him home to the Blue Demesnes.”
    “The herd?”
    ‘The local unicorn herd. They be all oath-friends with Neysa, and Neysa is oath-friend to my father Stile, so none would e’er do me harm. They would believe that Mach is me, under some hostile spell, so would take him home right away.”
    “And home is these blue demesnes? Where are they?”
    “North of the herd demesnes. In Phaze every type of creature of any significance has its own region, called its demesnes, and so do the Adepts, the leading magicians. Of course there be a number of unicorn herds, just as there be many werewolf packs, but the important ones to us be the oath-friends.”
    “Wolves too?”
    “It all dates back to when my father made the Oath of Friendship with Neysa, so powerful it embraced all the members of the Herd and the Pack too. Because I be the child of Stile, I can safely go anywhere in those demesnes, because no unicorn or werewolf would harm me, and no lesser creature would dare to, for fear of the Herd and the Pack. So Mach will be safe.”
    “If he took that path,” she said.
    “He has to have taken that path!” he said vehemently. “Otherwise—“
    “Surely he took it,” she agreed.
    “So we can go to the Blue Demesnes, and find hij there,” he concluded.
    “And these are north of here?”
    “Should be northeast of here.”
    “But—“
    “They be north of the Herd, but the Herd be east of the glade where we exchanged identities. That glade coincides with Mach’s room in the dome; that be why I was able to locate him there, and finally to achieve rapport with him. Since the two geographies be identical, I can find the spot here by taking the same route I would there.” He peered again into the darkening gloom. “I hope.”
    “There should be a map,” she said.
    “A map?”
    “A map of Proton. All planets have maps.” She touched buttons, and a screen illuminated. Soon the map appeared.
    Bane stared at it. ‘That be Phaze!” he exclaimed.
    “It says it is Proton,” she said. “See, here is our city, Hardom, with our vehicle location glowing.” She pointed to the blinking spark of light on the map.
    “That be the Harpy Demesnes!” he said. “Right above the Purple Mountains.”
    “Harpy Demesnes? Was the city named after the harpies?”
    “Impossible! There be no harpies in Proton.” But then he reconsidered. “Still, that does sound like har as in harpy, and since it be a dome—Har-dome. Hardom. I wonder.” He focused on the other points of the map. “Down here be the Mound Folk of Phaze—and here be Moudom! And here, farther to the east, be the demesnes of the Gnomes—and here be Gnodom! They do match!”
    “It really is a map of Phaze? This seems remarkable, if there has been no contact between the frames.”
    “Maybe not. Up until twenty years ago, the frames were more closely connected. There was a curtain that some folk could cross. My father crossed it, to woo my mother. How long ago were these cities named?”
    She touched another button. “It says three hundred years ago, for most.”
    ‘Then that’s it! They were named when Phaze and Proton were one, before they separated, and long before that separation became complete. The original settlers knew they were the same!”
    “This is very interesting,” she said. “My own planet has only one aspect.”
    ‘That’s probably the case with most—you call them planets?”
    ‘The satellites of other stars, far away.”
    He was distracted for a moment. “How far away be thine?”
    “About fifty light years.”
    He shook his head. “That means naught to me.”
    She smiled. “Magic means nothing to me, but I accept your information on it.”
    He returned the smile. “I question not thy word, Agape. And thou art not a human being?”
    “I am not. I assume this form so that I may participate without offense in this human society.”
    “Just as Fleta assumed