The Kingdom of This World tells the story of Ti Noël and the political turmoil in Haiti following the French colonial days. Ti Noël is a slave on a plantation in northern Haiti, then known as Santo Domingo. He participates in a rebellion against the French colonists. When his master flees to Cuba, Ti Noël is taken along and lost in a card game to a Cuban plantation owner. Ti Noël saves up his money and buys passage back to the now-free Haiti only to find that dictatorial King Henri Christophe has made slave labor of his fellow blacks. Henri Christophe is overthrown only for a mulatto upper class to rise and enforce labor on the darker-skinned blacks. At the end of his life, Ti Noël still stands up to call out a cry of rebellion to the world.

As the novel begins, Ti Noël is living on the plantation of a French colonist near the Cap, a city on the north coast of Santo Domingo. Another slave on the plantation, Macandal, gets his arm caught in a machine and it is crushed and later amputated. The one-armed slave is tasked with taking the cows to pasture, and in the foothills he discovers a wealth of plants of various kinds, including poisonous-looking mushrooms. Macandal disappears into the wild and begins planning a campaign of poisoning the whites and their livestock until someone learns that Macandal is responsible. He disappears again, but is finally captured and burned alive. There is a commotion at the execution, however, and the black slaves believe he has escaped as a supernatural hidden enemy of the slave owners.

Time passes. The French government orders slaves in the colonies to be released, and the plantation owners rebel. The slaves rise up in an open rebellion, which is initially crushed. Ti Noël's owner flees to Cuba with his remaining slaves, where he lives a life of hedonism tempered with prayer as he fears death coming nearer. He gambles away Ti Noël in a card game, losing him to a Cuban plantation owner. Ti Noël saves up his money to buy his way back to Santo Domingo, which has since been conquered by the rebelling slaves and where he believes he can be a free man.

When Ti Noël arrives at the now-deserted and ruined plantation where he once was a slave, he discovers that a rich aristocracy of blacks has risen under the rule of King Henri Christophe. However, Ti Noël is taken into slave labor, along with all the other residents of the northern region, to build a towering fortress atop a mountain, where the king and a large contingent can flee in case of attack. Under black rule, Ti Noël again finds himself enslaved. Ti Noël escapes as the work winds down, but the people of the land are unhappy with the king. Another revolt occurs, and the king shoots himself. For a while, Ti Noël is free, living in the deserted plantation and wearing one of the former king's robes. However, a new upper class arises from the lighter-skinned mulattoes on the island. As they parcel out the land and dictate forced labor for the people, Ti Noël calls to the sky with another cry of rebellion.