In the story The Chrysalids, Davie (the narrator) is, and knows several other youngsters who are, "different." They are considered by society to be "mutants" or "deviations," but Davie and his friends keep their secret from family and friends.
One of them has disappeared; no one has heard from him. After Sophie and other deviations have been discovered, Davie is worried that perhaps the boy who has disappeared has also been discovered.
Davie's Uncle Axel (who is the only adult who knows Davie's secret) promises that he will try to find out what he can, and whether the boy was taken because he was a "deviation."
In the meantime, it is discovered that Aunt Harriet's baby is a "deviation," and when she comes to Davie's mother for help, she is turned away by both of his parents.
All of these things are especially unsettling to Davie: he fears being discovered as well.
However, Uncle Axel finally comes back to him and tells Davie that a boy named Walter, about the age Davie had described, had been killed accidentally in a logging camp mishap, and that there is a good chance that this boy is Davie's missing friend. The family is sad for the loss of Davie's "friend" Walter, but relieved that he died from nothing other than an accident. (Had there been other circumstances, it could easily have been that Walter was a "deviation," a constant fear in this society.)
As it is, they realize the boy may have been related to Davie's grandmother because they both had the same last name: Brent.
In the future, the family feels it would be wise to know more about who is a relation so there is no worry or confusion of the same kind again.
Perhaps it is actually the fear of those who do not conform, who are mutants, that makes everyone want to know who their family members are, so they do not become involved in something illegal or unholy, and find themselves conspirators without knowing the truth of these people.