Many femme fatales go on fairly similar journeys. In the noir films in which they appeared in the 1940s and ‘50s — I’m thinking types like Phyllis Dietrichson in Double Indemnity (1944), Helen Grayle in Murder, My Sweet (1944), or Kathie Moffat in Out of the Past (1947) — they could often be found using their charm and beauty to seduce a hapless, too-trusting man (or men) into doing the dirty work required to get them something they desire, usually money beyond their wildest dreams. 

The production code firmly in place at the time made it impossible for them to get away with it, and that could — and still can — create uneasy friction. You want to celebrate the bold amorality of these women and their unwillingness to settle quietly in a world that tells them they ought to. But their inevitable doom can feel like a misogynist rejoinder from the cinematic powers that be. Their ultimate fates help capitalize on still-persistent stereotypes of women as inherently untrustworthy; a willingness to parlay one’s sexuality for personal gain is rendered a telltale sign of moral failure and not an admirably audacious attempt to outsmart an oppressive system. These movies reinforced a message that if a woman steps too far out of the societal confines created for her — if she has lasting power over a man — then she must be punished.

Still, it’s easy to have fun with this thorny, male-anxiety-informed character type that so enthusiastically deviates from the expectations of polite society. Decoy, a thriftily made 1946 noir written by Nedrick Young and directed by Jack Bernhard, isn’t very good, but it features who might be the nastiest, most exciting-to-watch femme fatale of the classic film noir era. Margot Shelby (Jean Gillie) doesn’t merely make easily duped men do her bidding: she delights in murder herself once she no longer needs them. She uses guns and cars as channels for her homicidal instincts with so much glee that, if there’s one thing you won’t forget about Decoy, it’s the maniacal cackle Shelby can’t help herself from letting out when she gets too carried away in her bloodlust.

Jean Gillie in Decoy.

All that bloodlust is borne, at least in the scope of the film, of some $400,000 she wants her hands on. It belongs to her one-time lover, Frankie Olins (Robert Armstrong), who’s currently on death row for committing a murder during the robbery of an armored car that netted him that eye-popping amount of money. He’s buried it somewhere deep in the woods. Shelby and her new boyfriend, Jim Vincent (Edward Norris), want it for themselves. After some scheming, they arrive at a sci-fi-esque conclusion. What if they were to wait for Olins to be rolled into the morgue, dead from all the gas he’d inhaled in the chamber, and then revive him with a toxin-reversing antidote called methylene blue Shelby’s passingly heard of? 

Decoy has a promising premise frequently given a lift by Shelby’s hot-blooded impulses and her florid way of speaking, which often returns to an impassioned refusal to go back to a drab, money-starved life. (She wants more of one where she can collect lots of more-than-$70 bottles of perfume, not just the one she braggadociously covets.) But the movie, made quickly by the penny-pinching B-movie studio Monogram Pictures, never carves out much of an identity for itself outside of Gillie’s performance and soap-operatic twists of the plot. It’s thought a lot about where it wants to go, and the big personalities to get it there, without much by way of actual character development or ways to drum up suspense for an objectively hare-brained plot. You aren’t immersed in the nightmare Young quickly devises; distance is generated instead, not helped by how most of the movie technically takes place in a flashback, the present-day vantage from which it originates making it clear that everything will end badly. 

Decoy was the first American movie in which London-born Gillie, who was married to the film’s director, appeared. (She gets a flashy “introducing” credit at the film’s start.) She’d only have one more movie to further her career in the states — the 1947 drama The Macomber Affair, in which she played a supporting role — before dying, in 1949, after a freak bout of pneumonia just a few months after her 33rd birthday. Before Decoy, Gillie had proven herself in the U.K. to be a gifted comic actress; this late-career change of pace showed an actress just beginning to test out what else she was capable of, tragically thwarted by forces beyond her control.