describes the people and landscape of British India in rich and vivid detail, the novel is primarily concerned with the growth of its hero. Kim is first seen as an aimless and conscienceless street boy of about thirteen. When last seen, at about age seventeen, he has become a man of purpose, responsibility, and integrity.
Kim’s parents are dead long before the story begins. His father resigned from his military regiment and became addicted to drugs and alcohol. At his death, he leaves Kim only a few papers, but he promises Kim that these will protect him under the sign of a red bull on a green field. Known as the "Little Friend of all the World," Kim easily makes new acquaintances. Near the Lahore museum, he befriends Teshoo Lama. Pitying the old Tibetan’s weakness and eager for adventure, Kim volunteers to replace the lama’s dead disciple. To pay for their pilgrimage (the lama seeks the River of the Arrow, where his sins will be washed away), Kim begs money from Mahbub Ali, who pays him to carry a message to another town. When Kim delivers the message, he learns that he has been employed as a British spy.
Shortly afterward, he sees a flag with a red bull and green field. He has found his father’s regiment. He is discovered by Father Victor and the Reverend Arthur Bennett. Despite Bennett’s desire to place Kim in an orphanage, Father Victor enters him in St.
Xavier school, and the lama promises to pay for his expensive education. Colonel Creighton and Mahbub Ali realize that, once educated, Kim will make a superb secret agent. Kim learns quickly, but the school’s many rules oppress him. During vacations, he runs off to join the lama on the road. He takes responsibility for the lama and saves Mahbub Ali’s life as well as that of another spy.
Kim’s education in school and on the road culminates in his final adventure in the hills. He convinces the lama to pursue his pilgrimage there, but, actually, Kim is on a mission with Hurree Chunder Mookerjee. They are pursuing a Russian and a French spy who are inciting Indian rulers to rebel against the British. Mookerjee, pretending to be a guide, leads the spies to Kim, who destroys their records, but the lama is injured, and Kim must exhaust his own strength in bringing the old man to safety. In so doing, he learns the answer to the question "Who is Kim?" which has haunted him throughout the novel.