Kathryn Sumner

Driving home one night in London, a woman hits a man who shouldn't be there.

In the Yorkshire countryside, working-class tomboy Mona meets the exotic, pampered Tamsin. To seal their friendship, Mona introduces Tamsin to her born-again Christian brother and helps her spy on her adulterous father. Bound together by their secrets, the two girls see their friendship deepen and enter into dangerous waters.

The Day of the Triffids is a BBC miniseries adaptation of John Wyndham's novel of the same name. The novel had previously been adapted by the BBC in a 1981 miniseries.