It's no secret that Agatha Christie did not like her popular Poirot character. She even (spoiler!) killed him off in a late 1940s novel.
And then kept writing about him. After all, her public loved, and still loves, him. (And publishers love following proven success with more of the same thing.)
But this created a problem. Her 1940s novels were definitely 1940s novel. When i first read (novel referred to above), i felt a dreamike disconnectedness. Poirot was still active in the 1960s and early 1970s; a novel written in the 1940s doesn't give the same feel. Christie also wrote a Miss Marple novel at the same time, but, since she did not kill the character, it's easy to disregard its tagline, Miss Marple's Last Case.
Third Girl is definitely a 1960s novel. The girls wore their hair long, loose, and straight, or maybe bouffant; drug culture and nonrealistic art were strong background elements. i'm unfmailiar with the "stepped from a VanDyck painting" fashion of the young men in the story, but, ok, that's undoubtedly a part of what Christie was seeing in the 1960s.
Third Girl is billed as Agatha Christie’s foray into the swinging sixties. And it is certainly a portrayal of the 1960s, as seen by an older generation who cannot understand why these young people won’t take a bath and get the hair out of their eyes. Taken purely as a mystery novel, however, Third Girl is enormously satisfying, a twisty puzzler that, for all its surface modernity, proves that nothing is more timeless than murder. from https://deadyesterday.wordpress.com/2020/03/22/third-girl-1966-by-agatha-christie/
In the Suchet film, numerous changes are made to the story. For a list, see here: https://en.wikipedia.org/wiki/Third_Girl#Adaptations_for_television The film is gorgeous. i actually like a few of the changes , such as a murder victim in the novel is NOT murdered. There also seems to be better closure with the criminals's story. The movie, as is the entire series, is well done.
However, the filmmakers
moved the setting back to the 1930s. In itself, that solves the problem presented by that novel from the late 40s, the one that killed off the character.
But overall, the timeshift isn't a problem. The side effect of Norma's changed hairstyle, a
chic period pouf instead of stringy unwashed hair, is disconcerting. And while Miss Lemon and Dr. Stillingfleet added greatly to the novel, the time change may not have made their absence necessary. i missed especially the fiery doctor, who appears all too seldom..
