The first two-thirds of "Things Fall Apart" is an affectionate description of the culture of an Ibo clan told from an insider's viewpoint, focusing on the life of Okonkwo, one of his tribe's most respected leaders. The customs and religion of the Ibo village are described with sympathy and simplicity, creating a sense of nostalgia for a way of life completely exotic to Western sensibilities, but making the reader feel the force and logic of a traditional culture seen from within. This idyllic description is clouded by the reader's awareness of the culture's fragility, a foreboding sense of pity and of looming disaster. Disaster comes, of course, in the shape of white missionaries. In the last part of the story, evangelizing Christians and English colonial administrators establish themselves in the Ibo village, and act to corrode and unravel the traditional life of the Ibo people. An escalating series of misunderstandings and conflicts between the whites and natives lead to the inevitable tragic ending. In the last paragraph of the novel, the perspective shifts suddenly to that of the English colonial adminstrator, and ends with one of the most powerful and affecting last lines of any novel I've read.
This book was thoroughly enjoyable, and I recommend it unreservedly.