This is something I've been mulling over for a few weeks, but I was prodded into writing by seeing Steven Riddle address the same issue (hat tip: Happy Catholic).
Mystery, the ever-popular series on PBS, recently ran a set of four new Miss Marple mysteries, all based on books that I'd read years ago. (I went through an Agatha Christie kick in my early teen years and churned through most of her works.) The four mysteries were Murder at the Vicarage, A Murder is Announced, What Mrs. McGillicudy Saw, and The Body in the Library. Murder at the Vicarage (barring the odd flashback sequences) and What Mrs. McGillicudy Saw were substantially the same tales I remembered. A Murder is Announced had some slight differences, and the denoument to The Body in the Library was so drastically unlike anything Dame Christie wrote as to send me out to the library searching for the original.
(I am sorry if I throw out any spoilers discussing the mysteries.)
The producers of Mystery have decided to spice up the Miss Marple cases by throwing in a few pairs of lesbians -- a move that is definitely unsubstantiated by the originals. In A Murder is Announced, there are a pair of spinsters who feature in the story -- Murgatroyd and Hinchliffe. In the book they are a dowdy old pair of friends, with nary a whiff of sexuality about them. Hinchliffe is indeed a mannish creature (Christie's description) and has nothing to do with men, but Murgatroyd is simply a frazzled, middle-aged bag of kindly fluff. They are housemates, an arrangement which is not commented on in the book. You'd think in a mystery set in the 1950s in which everyone's background is dug up, a lesbian pairing would be remarked upon openly, if it exists.
Not so in the tv series. Murgatroyd (what a name) is a slim and pretty young thing starting a lesbian relationship with the more masculine Hinchliffe (though they're trying to keep it a secret). She's a bit fluffy, but otherwise bears little resemblance to the woman in the book. And by making her Miss Marple's connection in the town, the movie eliminated the character of the vicar's wife, who was far more charming and interesting.
Still, perhaps I'd simply missed these sordid undercurrents as a twelve-year-old. But The Body in the Library made me cough on my iced tea in sheer confusion. You see, the producers had changed the identity of one of the murderers to create a lesbian couple killing in order to finance their escape from it all. Whoa, nelly! Not only was this far removed from anything I remembered of the original, but there were no clues leading up to this bizarre denoument (to guide us amateur sleuths in the viewing audience). Why go to such trouble to alter an already tightly-plotted mystery? It certainly wasn't flattering to the idea of lesbianism. Perhaps, as Dr. Johnson said, the wonder is not that it was done well, but that it was done at all. Maybe some liberal scriptwriter wanted to add more suspense to the tale and put in an "Aha! You're so close-minded you didn't even suspect this!" twist.
I did enjoy Geraldine McEwan's performance as Miss Marple, though. Re-reading the books, she's not exactly like the character Christie drew, but neither were these programs, so it doesn't really matter in the end, now does it?