The Girl From Monday

A creature from a planet orbiting Star 147X in the constellation "Monday" comes to Earth, seeking another creature from the same place who followed the same path long ago. She meets up with Jack Bell, an ad executive who secretly moonlights as the leader of a revolutionary cell. In the advertising world, the connection between value, youth, and sexuality are now explicitly interwoven: citizens are proud to be stock options whose market value goes up or down depending on their sexual activity, and having sex just because it feels good rather than because it increases your credit rating is against the law.