Hell's gate / Richard Crompton.

Mollel, "the Maasai warrior-turned-detective, has been banished from Nairobi, Kenya's bustling metropolis, to a small, fly-blown town on the edge of a national park. His career, he thinks, has taken a nosedive. His colleagues on the police force are a close-knit group and they have not taken kindly to a stranger in their midst. Mollel suspects they are guilty of the extortion and bribery that plague the force. But when the body of a flower worker turns up in the local lake, he begins to wonder if they might be involved in something even more disturbing"--Amazon.com.