The River Between explores tensions between two factions within the Gikuyu tribe in the early days of white settlement in Kenya. One group embraces the new religion of the missionaries. Their leader, Joshua, is a zealous Christian preacher. Inflexible and intolerant, he condemns the traditional native culture, which he regards as superstitious and sinful. The other group rejects Christianity (or in some cases, has rejected it after having initially been converted) and seeks to observe and perpetuate the traditions of the tribe.
Caught in the middle is Waiyaki, the central character. He has been educated at the Christian school, but returns to his village. He is committed to reconciling the two groups, and believes that the answer lies in education, which would enable people to acquire the knowledge represented by the white men, but also to retain many native traditions. He works tirelessly to establish schools and recruit teachers, and he earns the respect and confidence of most of the "traditionalists" in the tribe. But he confronts growing intolerance and animosity between the two groups, as well as personal animosity from some who see him as a threat, and in the end his attempt to bring the two groups together is seen as a betrayal.
The River Between is a good book, and in the end a tragic one. It is the first novel I have read by Ngugi wa Thiong'o, and I recommend it.