Aliens visit Earth to rediscover the secret of immortality which was found there millions of years earlier by another member of their race, but lost before he could reveal it to his home world.
Alán Salvó [Alan Strange] (descendant of Adam Strange in the 25th century); Tommy Parker; Howard Parker; Llalla (first appearance)
Synopsis
Tommy's father relates the story of Alan Strange, who stopped thieves from stealing some parastil, a rare metal used to make money in the 25th century.