The African Poison Murders — Elspeth Huxley

It is the stunning Janice West, with her dark eyes and husky American voice, who persuades Vachell to investigate the mysterious incidents spreading fear and alarm through the close-knit farming community of colonial East Africa. Considering the tangle of complicated and secretive relationships, plausible motives exist; but there's not a thread of definitive evidence to link the crimes together and reveal the perpetrator.

As Vachell works to put together the bizarre pieces of the mystery, he begins to suspect that he is intended as the next link in the killer's chain...