Boobeard + the Heroine
Okay yeah... well the Bluebeard stuff is in the public domain, I mean that metaphorically, but it was unforgivable for Lang to rip off Patricia Highsmith's story "the Heroine" just to include it as a laughable subplot of the movie that wasn't even properly developed.
just so everyone knows (and I will include spoilers), "the Heroine" was a short story about a congenitally deranged young woman who takes a job as a nanny for a family, and (I'm simplifying it, it's a really well developed psychosis) becomes worried she might lose her job, so she sets the house on fire in order to "save" the children from fiery death and secure the everlasting gratitude of the family.
Great story, terribly poorly rendered here - and it's no coincidence, Highsmith won the O. Henry award for the story only two years before this film came out, so it's not as if it was obscure.
BOOOOOOOO !!!