Efter en del googling för "cinderella city" och tidsresor, tror jag att det förmodligen är Fara Quotient av Annabel och Edgar Johnson. Denna utgåva hade ett grönt och svart omslag:
AttsökaefterolikafraserpåGoogleBöckervisarupptvårelevantautdragfråns.114av Science fiction för unga läsare , först den här:
Let us look at the three texts in more detail. Danger Quotient, by Annabel and Edgar Johnson, is a light atomic adventure novel for teenagers, with a slight romantic subplot. Set in the year 2127, 130 years after World War III, it depicts survivors who "live like earthworms" (4) in an underground complex in Colorado.
Och sedan den här:
He discovers his previous existence in the twentieth century as the multimillionaire Midas Forsythe, a developer who transformed Cinderella City, an enormous Donald Trumpish shopping mall
Och ytterligare sökning på Google Böcker ger några relevanta utdrag från boken Seniorplots: en bokpratguide för användning med läsare i åldern 15-18 , som att denna "Midas Forsythe" skapade det underjordiska komplexet i Colorado. Det var där Cinderella City var belägen, så även om de fragment som jag hittade inte anger detta, sätter två och två tillsammans föreställer jag att komplexet byggdes i den tidigare Cinderella City:
Radioactivity has doomed them to a highly computerized, well- regulated subterranean life in a complex that had been built more than 130 years ago before World War III by a mysterious visionary named Midas Forsythe. His uncanny foretelling of the catastrophe to come led him to build an underground community equipped with the latest technology, where he, his family, and world prominent scientists were able to escape the total destruction of the world and preserve the human species.
Och en av recensionerna på amazon nämner att huvudpersonen reser sig tillbaka i tiden:
The Danger Quotient by Edgar and Annabel Johnson. (Experiment Number 4(SCI) ) is 18, in a post-apocalyptic underground city where he and other genius "superkids" were created to rebuild the earth's ravaged ozone layer (destroyed in World War Three). Here people die in their thirties or even younger with symptoms of old age. A maverick, he instead uses a time machine created by his dead "big sister" to search for clues as to how people in the past managed to live so long. After a meeting with a street-smart young girl and her uncle in 1981 who give him the name 'Casey', he is sent bouncing around history, learning to care about people who treat him with the love he never got as an experimental child...
Här är en annan översikt över sammanfattningen:
Casey is eighteen years old in a post-nuclear world - where twenty is old age. Casey's real name is K/C-4(SCI). He's a supergenius, created in a test tube from the best genetic material available. He lives in an underground complex under what was once Colorado, along with other survivors of World War III. The colony's population is slowly dwindling. Casey himself is eighteen, and aging fast. According to the best calculations, he will die in exactly eight months and fourteen days. But why? Casey thinks the answer lies somewhere in the past, and he builds a time machine to take him there. The risks of time travel are enormous, yet Casey can't help himself. He becomes involved in the fate of a twentieth-century family, and with one girl in particular. It soon becomes clear that the future of Casey's colony depends entirely on the decisions he makes.