This Immortal was first published in 1966, my Panther edition paperback a couple of years later (it cost me five shillings, which is 25p in new money). The last time I read it was about forty years ago, so I was pleased when it was chosen as the monthly read for the Classic Science Fiction discussion group.
The story is set on a future Earth almost destroyed by a global nuclear war. The majority of the descendents of the survivors are now living on other planets, courtesy of the amiable Vegan aliens (as in, from Vega, rather than plant-eaters) who are fascinated with Earth and its history, but some still remain. One of them is the hero and teller of the tale, Conrad Nomikos, the Commissioner of Arts, Monuments and Archives for the planet. He is somewhat displeased to be called from his extended honeymoon to act as a tour guide to Cort Myshtigo, a wealthy and influential Vegan visitor. As the tour proceeds it becomes clear that there are many undercurrents, with threats to the lives of Myshtigo and Nomikos himself, but not until the end of the story is the real purpose of the Vegan's visit revealed.
Zelazny's writing style – laconic understatement laced with dry humour – is the main pleasure of the story. This flows rapidly, emphasised by the lack of any chapters, just line spaces to indicate a change of scene. Nomikos is a somewhat elliptical narrator, only gradually and indirectly revealing that he is very odd indeed – a man of indeterminate age, unusual abilities and many previous identities, who played a major role in the historic campaigns to prevent the Vegans from buying up the whole of Earth and to encourage the human emigrants to return home.
The inclusion of a variety of bizarre mutant humanoids and animals living in the still-radioactive zones seems a bit dated now, but was a standard SF assumption at the time. It did not detract from my pleasure in reading this story again, and I finished it in a couple of sessions.