In 1940 Kenya as their country prepares for war, the local aristocratic social set lives a decadent, self-indulgent lifestyle, that leads to murder. The same events were also dramatised in the feature film White Mischief, which was released seven months after the first transmission of The Happy Valley.
English aristocrat Tony Last welcomes tragedy into his life when he invites John Beaver to visit his vast estate. There Beaver makes the acquaintance of Tony's wife, Brenda. Together, they continue their relationship in a series of bedroom assignations in London. Trusting to a fault, Tony is unaware that anything is amiss until his wife suddenly asks for a divorce. With his life in turmoil, Tony goes on a haphazard journey to South America.
