Dr. Fynn chronicles Shaka's life and rise to power starting with the meeting and affair between Nandi and Prince Senzangakona of the Zulu tribe. Despite Senzangakona's marriage to another and Nandi's fathers attempts to marry her off, they continue to meet, and Nandi becomes pregnant. She gives birth to a boy who she names Shaka, meaning “beetle.”

Nandi's father demands that the Zulu recognize Nandi and the baby Shaka. Senzangakona, now king of the Zulu, takes her as his wife. However, he continually abuses Nandi, until one day Shaka cannot take it anymore and threatens his father to kill him. Nandi and Shaka flee and return to her people, but find themselves the object of scorn, so they flee once again.

Shaka has grown into a fine young man. Senzangakona invites him to return to Zululand and become his heir. Shaka returns but disrupts a ceremony and is forced to flee for his life. He is taken in by another tribe and trained as a foot soldier. However, he clashes with the generals over how to fight.

Shaka goes deep into the Nkandla forest and asks a blacksmith to forge a stabbing spear, named “ixwa.” Shaka returns to his regiment and convinces the king that his new method of warfare is worth trying. His new regiment are used against the Zulu and win the day. Soon after, Senzangakona dies and Shaka takes the throne for himself.

Farewell and his men become Shaka's guests. Shaka is severely wounded during an assassination attempt and Dr. Fynn saves his life. In gratitude, Shaka gives Farewell both land and permission to hunt elephants for ivory. Meanwhile in Cape Town, Shaka and Farewell are both proclaimed dead.

Farewell and his men establish Port Natal on the coast. However, the men are restless, and they wish to return home, but Shaka forces them to join him in a war against another tribe. He uses them and their cannon to force the enemy into making a first move. This results in an overwhelming victory for the Zulu.

After burying the dead, Farewell asks for help in building a boat to return to Cape Town. Shaka agrees, but he keeps with him most of the party —including Dr. Fynn— as hostages. On returning to Cape Town, Farewell and a Zulu delegation are despised by Lord Somerset. Shaka learns that his wife has given birth to a son. He orders to kill the child, so he can not threaten Shaka's reign in the future. Nandi falls ill and Shaka begs Dr. Fynn to save her.

A long-ago foretold prophecy comes to pass when a proposal to negotiate a peaceful alliance between the Zulu Empire and Great Britain fails. Zulu Queen Mother Nandi finally dies, and Shaka, knowing his own fate is sealed, goes into a self-destructive rampage. Farewell returns to Zululand and meets with Shaka, who abandons his reign of terror. Shaka is finally murdered and his empire falls apart.