Footsteps in the Dark is a 1941 mystery film directed by Lloyd Bacon, starring Errol Flynn.
Francis Warren (Flynn) is a financial advisor who handles the investment portfolios and tax shelters of New York's wealthy. He lives in a mansion with his gorgeous wife Rita (Brenda Marshall) and surprisingly tolerable mother-in-law Agatha. What Rita and Agatha don't know is that Francis has a secret life: he writes detective fiction under the pen name of "F.X. Pettijohn". What's more, his latest novel Footsteps in the Dark includes thinly veiled caricatures of many members of the Long Island smart set that Francis socializes with. Agatha is talking about a libel suit, if only they can figure out who F.X. Pettijohn really is.
But that's not all! Francis also is an amateur sleuth! He tags along with the police—who know him as F.X. Pettijohn—to crime scenes, ostensibly to do research but really to investigate their cases for them Jessica Fletcher-style, , much to the irritation of Police Inspector Mason (Alan Hale). All this he does without Rita knowing, going so far as to sneak in through second-floor windows of his house late at night so she doesn't hear him come in.
A man named Leopold Fissue comes to see Francis during Francis's day job as a financial advisor. The obviously shifty Fissue wants Francis's help in liquidating some uncut diamonds. Francis is suspicous, and when Fissue turns up dead on his yacht Francis is really suspicious. The police write Fissue's death off as a heart attack, but Francis doesn't buy it, and he follows the clues to a burlesque dancer named Blondie White who Fissue was dating.
A rare comedy for Errol Flynn, who spent most of his time at Warner Bros. in action, cowboy, or war movies. Ralph Bellamy appears as Dr. R.L. Davis, a dentist who knows more than he's telling.
- The Alibi: Francis zeroes in on Blondie White pretty quickly, particularly after seeing her fuse two matches together like the ones he found on the yacht. But she has a cast-iron alibi: she was getting her teeth fixed at the dentist. It turns out that Blondie and her dentist were in on it together.
- Alone with the Psycho: Subverted in that Francis deliberately arranges to be alone with the psycho but has Wilfred bring the cops to Davis's dental practice at a pre-arranged time.
- Amateur Sleuth: Francis. As is so often the case with this trope, the amateur (in this case an author of detective fiction) is better at the sleuthing than the cops are.
- Be a Whore to Get Your Man: When she becomes convinced that Francis is cheating on her with a stripper, Rita decides that Blondie must be offering Francis something she isn't providing. She winds up practicing stripper moves in her bedroom, only to be embarrassed when the butler intrudes.
- Bland-Name Product: A note is formed out of a page from "World Geographic Magazine"—National Geographic, of course.
- Burlesque: Blondie is the star of a burlesque show. She basically sings while wearing a corset.
- Cut-and-Paste Note: A variation on this in which Francis gets a note from the killer that isn't a cut and paste note, but rather a note in which most of the words on a magazine page have been scratched out, leaving only a few visible to form a threatening message. This backfires when Francis remembers where he last saw a copy of World Georgraphic Magazine, namely, in Dr. Davis's office.
- Enter Stage Window: Francis routinely does this after his nighttime detective excursions, climbing a ladder to his second-floor bedroom so no one sees/hears him coming through the front door.
- Everybody Smokes: It's 1941, so apparently the dentist will offer you a cigarette and smoke along with you while you sit in the chair in his examination room.
- Fake Action Prologue: Two men dressed in dark clothes creep across a lawn at night. One climbs a ladder to a second-floor window, sees a beautiful woman sleeping, climbs through the door—then puts on pajamas and gets in the other bed. It's Francis, coming home from his secret detective escapades.
- Fingertip Drug Analysis: When Francis is not killed by the poison Dr. Davis injected him with, Davis tastes it. Francis figured out what was up and switched out the poison with water while Davis's back was turned.
- Grande Dame: Agatha, Francis's snooty mother-in-law, who calls Francis a "traitor to your class" when she finds out he's F.X. Pettijohn.Agatha: People in our set don't go around shooting other people!
Francis: (to Hoppy the policeman) Of course we don't Hoppy, we only bore them to death.
- Have You Told Anyone Else?: As Francis makes some extemely accurate hypotheses about how Blondie and her accomplice killed Fissue, Davis says "Knowing so much about the Fissue murder, and Miss White's accomplice, I suppose you've told the police about it?" Francis answers that he hasn't. Subverted in that Francis does this deliberately to get Davis to unmask himself.
- Inspector Lestrade: Police Inspector Mason, who grudgingly tolerates Francis's apperance at crime scenes. He spends a good chunk of the movie dismissing Francis's theory that Blondie killed Fissue with an undetectable poison, until the FBI calls and tells Mason that they were in fact investigating Fissue for diamond smuggling.
- The Lancer: Mr. Wilfred, Francis's chauffeur. Wilfred also is his secretary who takes his dictation when Francis is writing novels, and he's also Francis's sidekick and lancer when Francis is out doing detective work and chasing bad guys.
- Match Cut: From Blondie gyrating onstage as part of her burlesque act, to Rita doing the same in her bedroom, trying to come up with a way to seduce her husband.
- Pen Name: Francis writes murder mysteries under the name F.X. Pettijohn.
- Roman à Clef: The book Footsteps in the Dark contains some thinly veiled caricatures of the people that Agatha socializes with. A particularly annoying Rich Bitch named June Brewster is "Jane Wooster" in the book.
- Sequel Hook: The film ends with Rita, who has found out about Francis's secret life, dashing out to investigate an ax murder with him. Plans for a sequel to this movie were abandoned when it did mediocre box office.
- Sleeping Single: As usual per the 1940s, Francis and his smoking hot wife sleep in separate beds.
- Title Drop: Many references to F.X. Pettijohn's thriller Footsteps in the Dark.
- Visual Title Drop: As opening title "Footsteps in the Dark" pops up onscreen we see...footsteps in the dark, namely two pairs of feet walking across some grass at night. It's Francis and Wilfred coming home from detective work.