The Narrator is a British foot soldier who serves in Her Majesty's occupational army in India. Speaking in a working-class Cockney dialect, he shares his memories of fighting in a hostile, blistering tropical climate where the troops rely heavily on local workers. He initially holds prejudiced views toward the Indian population and openly admits to mistreating the regiment's water-bearer before an intense battlefield encounter challenges his assumptions.

Gunga Din is the regiment's Hindu water-bearer, or "bhisti," attached to the British occupational forces in India. He wears only a twist of cloth as a uniform and carries a heavy, fifty-pound goatskin bag called a "mussick" to supply the troops. Despite physical mobility challenges and constant verbal and physical abuse from the British soldiers, he remains steadfast at his post just behind the front lines, demonstrating quiet courage during combat.