The novel is set on a plantation owned by a man named Waller in the Southern United States in the early 1850s.

The narrator and protagonist of the story is a young female African-American slave named Sarny.

Sarny first sees Nightjohn when he is brought to the plantation with a rope around his neck, his body covered in scars.

So, at night and whenever he has the chance, John begins teaching Sarny the letters of the English alphabet.

This book was followed by a sequel called Sarny, a Life Remembered in 1998 The novel was adapted as a TV film which aired on the Disney Channel starring Carl Lumbly as John, Beau Bridges as the slaveholder, and introducing Allison Jones as Sarny.