The story follows Claire, the Birthmother of Gabriel, who was marked for "release" in The Giver before being taken out of the community by Jonas.

Then, she meets an evil entity, Trademaster, which offers to take her to her son if she trades her youth.

That destroys the Trademaster, and when Gabe returns home, Claire has turned back into a young woman.

"[3] Initially intending to center the book on Gabriel and his determination to discover his past, Lowry instead found herself being drawn to write more about Claire.

[5][6] A reviewer for The Washington Post wrote that the book had a "quiet climax", stating that the ultimate "power of this parable" is that "It confronts us with some of the choices we are making and plays out the consequences.

"[7] Robin Wasserman of The New York Times commented that Son did well as a standalone novel and praised Lowry's descriptions in the book.

[2] The Boston Globe criticized the book's "over-elaborations and pacing" while writing that "overall the journey is still worth the effort".

[8] The AV Club commented that while the book could have used more world-building, it is also "just plain good young-adult literature".