The novel traces the adventures of Peekay, an English-speaking South African boy, from age five to age seventeen, from the year 1939 to 1951. After his mother suffers from a nervous breakdown, the five-year-old Peekay is brought up by his Zulu nanny Mary Mandoma and his Granpa on a farm in the province of Natal. Soon after, he is sent to an Afrikaans boarding school, where--as the youngest of all the students, and the only English-speaker--he is brutally tortured by the other boys. The Judge, a senior boy called Jaapie Botha, and his so-called "stormtroopers" punish Peekay for his bedwetting habit and his circumcised penis by means of constant verbal and physical abuse. They call him derogatory names in Afrikaans such as "pisskop" (piss head) and "rooinek" (redneck), a term used for Englishmen during the Boer War (fought between the British and the Boers, or Afrikaners). The Judge, who wears a swastika tattoo on his arm, convinces the innocent Peekay that Hitler is on a mission to march all Englishmen into the sea and to restore glory to the Afrikaners. Mevrou, the Afrikaans woman who runs the boarding house, walks around brandishing her deadly "sjambok" (cane stick), instead of offering solace.

Peekay returns home after his first year of school, and his nanny commissions the famous Black chief Inkosi-Inkosikazi to solve Peekay's bedwetting dilemma. Not only does Inkosi-Inkosikazi manage this, but he also opens Peekay's mind to a special place of "dreaming"-a place of three waterfalls and ten stones-where Peekay may always find him. Peekay returns to school the following year with his problem solved, with Granpa Chook one of Inkosi-Inkosikazi's magic chicken, and with the independent spirit he refers to as the "power of one." Granpa Chook becomes Peekay's only friend at school, and Mevrou allows him to live in the kitchen where he keeps the cockroaches at bay. Peekay excels at school, yet he has learnt that surviving the system means one has to adopt a camouflage-he thus hides his brilliance. Nevertheless, he soon finds himself doing all the Judge's homework, which only serves to increase his intelligence. This does nothing to quash the Judge's hatred for Peekay-on the contrary, at the end of the schoolyear the Judge forces to Peekay to eat human feces, and he kills Granpa Chook with a catapult. Traumatized, Peekay longs to arrive home to his nanny's embracing arms. But Mevrou tells him that there has been a change of plans: he is to head to the Eastern Transvaal town of Barberton, where his Granpa awaits him. Peekay's name is coined by Harry Crown, a Jewish man where Mevrou takes Peekay to buy shoes before the trip home-Harry Crown says that "Pisskop" is not a respectable name for a young man, and dubs him "PK" instead.

On the train to Barberton, Peekay meets Hoppie Groenewald, boxing champion of the railways. Hoppie shows Peekay his boxing gloves, and invites the boy to watch him box a man called Jackhammer Smit in Gravelotte, a stop on the way to Barberton. Peekay's dream to become welterweight champion of the world is born. He commits Hoppie's advice-"First with the head, then with the heart"-to memory. At the Barberton train station, Peekay's mother welcomes him-she has returned from the mental institution, and has become a born-again Christian. Peekay discovers from Dum and Dee, the Shangaan kitchen servants, that Peekay's mother dismissed his nanny because she refused to give her life to the Lord. Peekay's mother begins trying to proselytize Peekay, but he tells his mother that the Lord is a "shithead." In the hills behind his new house, Peekay meets an old German music professor, Karl von Vollensteen, who introduces himself as Doc and explains that he collects cacti. Doc and Peekay become firm friends (along with Mrs. Boxall, the town librarian), and when Doc is taken to the Barberton prison since he never registered as a foreign alien, Peekay visits him for music lessons. The prison has a boxing squad where Peekay begins lessons under the special instruction of a Cape colored man, Geel Piet. Peekay quickly develops into an outstanding boxer, leading the team-the Barberton Blues-to victory. Peekay has great compassion for the Black prisoners, and works out a black market scheme with Geel Piet and Doc for tobacco and letters. In such a way, Peekay becomes a legend among Black South Africans - they believe he is a chief, the "Onoshobishobi Ingelosi" or "Tadpole Angel." One of the white prison wardens suspects that some illegal activity is underway, and one night Peekay discovers Geel Piet has been murdered in the boxing gym by the violent warder Borman. World War II ends, and Doc finds himself free once again. Doc, Mrs. Boxall, and a Jewish schoolteacher Miss Bornstein develop Peekay's precocious intellect through music, literature, chess, and science. To the delight of the town, Peekay passes his Royal College of Music exams and also wins the Eastern Transvaal under-twelve boxing title. With the help of his mentors, Peekay wins a scholarship to the prestigious Prince of Wales school in Johannesburg.

Book Two of the novel describes Peekay's experiences at the Prince of Wales school. He quickly partners up with the son of a Jewish multimillionaire, Morrie Levy. Peekay and Morrie take the school by storm-Peekay's boxing talent reforms the pathetic Prince of Wales boxing team, and Morrie becomes Peekay's manager. Soon the two boys have a lucrative gambling business set up, as well as all kinds of other "scams" which bring in enough money for Peekay to begin boxing lessons with South Africa's top coach, Solly Goldman. Peekay becomes a stranger to failure, excelling at boxing, rugby, and academics. However, he must face Doc's death towards the end of his school career as well as the disappointment of not winning a Rhodes scholarship to attend Oxford University.

Book Three traces Peekay's life in Northern Rhodesia (present-day Zimbabwe) where he takes on a dangerous (but lucrative) job as a "grizzly man" in the mines in order to build up his body for his boxing, and to earn enough money to pay his way through three years at Oxford. He forms a close friendship with a Russian miner, Rasputin, who eventually saves Peekay during a mining catastrophe, killing himself in the process. Peekay recovers but, before leaving the mines, he discovers that he has been working for his old nemesis, Jaapie Botha. Peekay fights Jaapie and knocks him out. Over Botha's swastika tattoo, Peekay chisels a Union Jack and the letters "PK".