One of my ongoing writing projects is a novel that riffs on the premise of a pair of female twins, one good, one evil. I’m aware this is well-worn territory in thrillers, and was happy to recently discover the 1947 film “The Dark Mirror”, which operates in the same space. (It’s free on youtube.)

As with a lot of these mid-20th-century films, there’s little in the plot that will surprise you, but it’s a fun, engaging flick, replete with all the twin-trickery you’d expect, plus a dose of psychological rumination and murder.

The actress Olivia de Havilland plays both twins and are a lot of on-screen moments where the characters appear together and interact. Presumably, the filmmakers shot the scenes separately, and then edited them into one. Somehow that “elbow grease” approach amazes me more that the CGI effects that would be used today.

Another possibility is that Olivia de Havilland herself had an evil twin sister who was never spoken of publicly but brought into use for the filming of this movie. Until she went off on a crazed murder spree. I like that possibility.

The attached photo is one of the less convincing of these edited together scenes, but still, you gotta respect the effort.