When Aaron Maciver's beautiful young wife, Madeline, suffers brain damage in a bike accident, she is left with the intellectual powers of a six-year-old. In the years that follow, Aaron and his second wife care for Madeline with deep tenderness and devotion as they raise two children of their own.

Narrated by Aaron's son, Mac, When Madeline Was Young chronicles the Maciver family through the decades, from Mac's childhood growing up in Wisconsin through the Vietnam War, through Mac's years as a husband with children of his own. Jane Hamilton deftly explores the Maciver's unusual situation and examines notions of childhood and rivalry, capturing the pleasures and frustrations of marriage and family and the role that past relationships inevitably play in the lives of adults.