Kimball O'Hara, an orphaned boy living in colonial India, becomes entangled in the 'Great Game' of espionage while searching for his own identity. Raised as a vagabond in the streets of Lahore, Kim encounters a Tibetan lama and joins him on a quest across the subcontinent. As he travels, Kim is recruited by British intelligence, forcing him to navigate the complex divide between his Irish heritage and his deep affinity for Indian culture. The narrative follows a linear progression, utilizing a third-person perspective to capture the vast social and political landscape of the British Raj.

Readers often highlight the intricate world-building that brings the landscape of colonial India to life with remarkable clarity. Discussion frequently centers on the moral ambiguity of Kim's role as a spy and how it conflicts with his spiritual education under the lama. Critics frequently note the balance between the picaresque adventure elements and the deeper philosophical inquiries regarding the nature of the self. The text is often praised for its ability to capture a specific historical moment without relying on simplistic portrayals of its characters. Many readers find the interplay between the protagonist's dual identities to be the most compelling aspect of the narrative.