Kimball O'Hara, an orphaned boy living in the streets of Lahore, finds his life transformed when he becomes the disciple of a Tibetan lama and simultaneously enters the world of British espionage. Kim navigates the complex social and political landscape of colonial India, balancing his spiritual devotion to the lama with his training as a secret agent for the British government. The narrative follows his development from a street-smart vagabond into a man capable of navigating multiple cultural identities. The story utilizes a third-person omniscient perspective to capture the vast scale of the Indian subcontinent and the intricate web of the Great Game. The protagonist faces the logical constraints of a world divided by caste, religion, and imperial loyalty, forcing him to reconcile his dual existence.

Discussion often centers on the vivid atmospheric rendering of India and the complex moral ambiguity inherent in the protagonist's dual roles. Readers frequently highlight the balance between the spiritual quest of the lama and the pragmatic, often cynical, nature of the espionage plot. Critics often examine the text as a reflection of imperial attitudes while acknowledging the depth of the character development. The pacing is noted for its deliberate, observational style that prioritizes cultural immersion over rapid action sequences. Many readers find the interplay between the protagonist's street-level perspective and the broader political context to be the most compelling aspect of the work.