Most colonial history has the rejects of the imperial society setting out to the colonies to better themselves, but Kenya between 1900 and 1940 proved a rare exception when a significant number of wealthy aristocratic English moved to the 'White Highlands' to settle. Others were found to do the actual work of ranching or coffee-growing and there was little for the rich to do except be idle. So grew the legend of the 'Happy Valley ' set, where drugs and alcohol fuelled continuous debauchery.
By the time the events covered in this movie occurred, the 'Happy Valley' period was pretty well over with several of the leading lights having succumbed to the rigours of the lifestyle. But Erroll (Charles Dance, charming) a veteran of the Valley is still surrounded by admiring women and has little trouble attracting Diana Broughton (Greta Scaachi, sizzling) when she arrives in 1940 from England to escape the war. Her husband Sir Jock (Joss Ackland, his best performance ever), 30 years older, knows Diana married him for money and security. She knows Erroll is broke but thinks Jock will pay her off. What she doesn't know is that Jock, through bad luck and mismanagement, has lost most of his considerable fortune (he once owned a good slice of Cheshire) and looks like losing the rest. (The film does not mention that the real Sir Jock had by 1940 committed serious fraud on at least two occasions to get himself out of financial difficulty).
In the film, Jock takes a while to realise what is going on, and then appears to accept the situation, even hosting a dinner at the Muthaiga Club in honour of the happy adulterous couple. Next morning Erroll is found shot dead in his car a couple of miles from the Broughton's house in suburban Nairobi. The case against Jock is not strong, and not carefully put together. He is represented by a first-rate South African trial lawyer, Harry Morris (Ray McAnally, in an uncharacteristically weak performance), who has little trouble evoking the sympathy of an all-white settlor jury.
The aftermath, for evident artistic reasons, is altered for the film, but the sense of it is still there. Within a short time Jock is dead, and Diana marries the eccentric Gilbert Colville (John Hurt, convincing), who is the biggest rancher in the colony. The last scene, where Diana comes across a cocktail party being held in a graveyard on the shores of Lake Naivasha at the request of one of the deceased, an alumni of Happy Valley, is quite surreal, and somehow captures the evanescence of it all, the fleeting moment between birth and death we call life. This part of Africa is sometimes said to be the Garden of Eden, the paradisaical place where mankind originated, and it's a truly beautiful place, but it's also clear the serpents were there all along.
Since this movie was made, a new theory about Erroll's death has emerged; that he was done to death by the British Security services as it was thought his fascist sympathies would make him likely to pass intelligence to the Italians (Erroll was a deskbound officer in the army). A lady called Eroll Trzebinski, resident in Kenya for 30 years, published a book 'The Life and Death of Lord Erroll' in 1999. Ms Trzebinski has written three other books including a well-received biography of Karen Blixen's lover Dennys Finch-Hatton. Well, I suppose it's no less credible than the theory Diana did it.
PS Another version of the story is told by Julian Fellowes in his "Most Mysterious Murder " TV series (2005). It's not a patch on this one but pretty convincingly identifies Jock as the culprit, with Diana accessory after the fact.