Dearth S is set in a post-apocalyptic world where the human population is in steady decline.
In this desperate times, Women only choose Alpha males to reproduce.
So the lower class males created an Alliance and waged war against the Alpha males.
The Alliance produced The Four Great Doctors and created Synonyms to calm the rest of the lower classes.
These Synonyms can only reproduce with the man they were born with.
This incest behaviour pissed the Alpha males and decided to fight back.
This caused The Four Great Doctors into hiding, which halted the production of the Synonyms.
You're a member of the Alliance who is searching for his lost Synonym.
Lower classes can only reproduce with the Synonym they were born with, so it is crucial for him to find his lost Synonym.
What's a simple wish of getting his Synonym back, would prove to be a lot more "thrilling".​