Imperial Earth is the fascinating odyssey of Duncan Makenzie, traveling from Titan, a moon of Saturn, to Earth, as a diplomatic guest of the United States for the celebration of its Quincentennial in the year 2276. Titan, an independent republic, was originally colonized from Earth three generations earlier. Duncan's initial challenge is to prepare, physically and intellectually, for the 500-million-mile trip to Earth. Once there, he is caught up in a sweep of new experiences, including the social and political whirl in Washington, a strange visit to a carefully preserved ancient city once prominent in the 20th century, and a search for and meeting with a woman he loved since she visited Titan years before.