Rex Brandon #5: Black Sport

Peter Cradling, a geologist and diamond expert said goodbye to his fiancée, Lesley Fane — possibly for the last time. His flight bound for the United Kingdom never reaches its first refueling point in Northern Rhodesia. In addition, the pilot never sends an S.O.S.
With nowhere to turn, Lesley seeks out her uncle's friend, geologist and big-game hunter Rex Brandon. The search for survivors — and the missing diamond samples — commences. Once underway, Brandon realizes the hair-raising adventure may end in death for himself and his companions.