A Donut Hole in a Donut’s Hole

Defining the Whodunnit

McKegg Collins
13 min readNov 23, 2022


You have been cordially invited to a lovely dinner at the magnificent mansion of a wealthy benefactor. In attendance are an eclectic and suspicious group of people all with motivations against their gracious host. What starts as an enjoyable evening ends in tragedy. The lights go out, a scramble ensues, and by the time the lights come up, your host lies dead in the center of the table. All are suspects and the night is far from over.

The mystery film is one of the more intricate subgenres by design. Clues, suspects, and the overall sense of intrigue keep the audience on a path toward the ultimate solution. As a result, the donut hole at the center of the mystery continues until you find a smaller hole in the center. Until finally we get to the donut hole in the donut’s hole: the Whodunnit.

The Whodunnit often refers to the classic closed-room, Agatha Christie-style mysteries. With the release of Kenneth Branagh’s Murder on the Orient Express in 2017 and Knives Out in 2019, the Whodunnit is gaining a resurgence. However, when defining and looking for Whodunnits, the internet seems to be a little confused about what actually constitutes a Whodunnit. With Glass Onion releasing today, bust out your magnifying glasses, cause we’re going to crack this case once and for all.

Vital Clues vs. Red Herrings

For my DND Nerds out there, check out Dimension 20’s Mice & Murder!

While there are a lot of elements that go into a mystery, there are a few specific genre elements that exclusively make it a Whodunnit. So let’s get into what a Whodunnit definitely is and what it is NOT:

A Whodunnit Is:

A Mystery, Typically a Murder

Features a Large Ensemble of Potential Suspects/Victims

Takes Place Within a Centralized Location

Always Has a Solution

A Whodunnit is NOT:

A Straight-Down-the-Line Detective Noir — (Chinatown, The Maltese Falcon, Brick, anything with Philip Marlowe) While whodunnits almost always feature a detective they are very rarely the full focus of the mystery itself. So notorious detectives like Sam Spade, Philip Marlowe, Jake Gittes, etc. do not count. While great mysteries, they are not in the same vein as a Whodunnit.

A Courtroom Drama — (Witness for the Prosecution, 12 Angry Men, Where the Crawdads Sing) While courtroom dramas often have an inherent mystery surrounding them, they are more the result of a Whodunnit than an actual Whodunnit. In courtroom dramas, the ensemble usually consists of the legal team and the defendant, and the primary focus is more focused on whether or not ONE person did it over trying to find out who did.

A Globe-Trotting Conspiracy Thriller — (Most Hitchcock, Charade, Blow Out) While there are Whodunnits that hop around locations, they are not going all over the world to get their mystery solved. A central conspiracy often involves several people as opposed to one set culprit and thus is much grander than the typically intimate scale of a Whodunnit.

Ambiguous — (Zodiac, Memories of Murder) Extremely good movies, but not Whodunnits because they don’t have an answer. The ambiguity of the unknown is what makes those movies so effective and terrifying on their own, but wholly ineffective as Whodunnits.

From the Perpetrator’s Perspective — (Silence of the Lambs, Gone Girl, The Vanishing) While fantastic films, they don’t offer a whole lot of mystery seeing as we know who the killer is and often follow them as a central character. After all, it’s not much of a Whodunnit if we already know who did it.

A Murder Most Foul

Green For Danger (1946)

In order to have a Whodunnit, there must be an It that’s been Dunn. It is the bread and butter, spread on an unusually sharp knife, of the Whodunnit. A group of people brought together to some mysterious place for one reason or another, and, of course, the murder. Yes, the Whodunnit is always centered on murder. Once the body drops, we are off to the races. Though it may not be the last victim before the night is through.

Sidney Gilliat’s Green For Danger presents its murder in the form of what appears to be an accident. A postman dies on the operating table at a village hospital. While deemed an accident, many of the doctors and nurses suspect something more nefarious afoot. As their paranoia tears them apart, they try to uncover what happened and exactly how it managed to sneak past all of them.

The murder that sets Green For Danger’s plot in motion is the perfect setup for a Whodunnit: a man dies under mysterious circumstances, some doctors sense foul play, and eventually, the culprit is revealed. These are the core values of the Whodunnit’s ultimate structure and predicates all that comes next.

Said mystery also usually takes place over the course of a short period of time, from as short as one evening to as long as a week or two. But never more than that as the story teeters closer into serial killer/police procedural territory and thus moves away from the Whodunnit. A murder, especially one that is often witnessed by the audience and the characters has a sense of immediacy to it, propelling its characters forward to try and solve this crime to save themselves and possibly save others.

While there are many elements that make Green For Danger an exemplary Whodunnit, it is the initial death that makes it stand out. A crime so silent, but deadly, it kicks off for the characters and the audience a wave of intrigue. The mystery is paramount as it’s the entire driving force of the narrative. It’s the puzzle that the audience rushes to solve before it’s over, oftentimes realizing at the last second, that the solution was right under their noses.

Round Up the Usual Suspects

Knives Out (2019)

What makes the Whodunit one of the most fun genres is its distinct power to attract a vast and varied cast of beloved character actors all at each other’s throats. The core of the Whodunnit lies in its ability to provide a well-formed collective (in which there is a 25% chance that one of those people is Dame Maggie Smith) of a literal murderer’s row of suspects to keep you guessing until the very end.

Knives Out perfectly exemplifies the power of the ensemble by assembling a litany of actors from legends like Jamie Lee Curtis, beloved character actors like Michael Shannon, and blockbuster stars like Chris Evans. They all come together to play various members of the Thrombeys, an upper-class family built on the back of prolific mystery writer Harlan Thrombey. Until Harlan’s murder on the night of his 85th birthday forces it to all come crashing down.

Writer/Director Rian Johnson kicks Knives Out off by using its cast to lay out its mystery while also introducing themselves. Every family has its politics within it and the Thrombeys are a ruthlessly petty and competitive bunch. In fact, in atypical Whodunnit fashion, the Thrombeys are introduced one by one, through the interrogation by the police (and our instantly iconic detective Benoit Blanc), demonstrating their own isolation from each other. By using them to set up the initial mystery, Johnson wonderfully layers underneath that exactly who these people are, how they feel about each other, and, most importantly, what their motives are.

This is why, once everyone is introduced, Knives Out pulls the rug from the audience by revealing the culprit at the end of the first act of the film. Harlan’s caregiver Marta, played in a breakout performance from Ana De Armas, is the only character not in the family and the person we follow from the start. Though her crime was accidental, she is still set into a world where she is the outsider and struggles to keep her head above water against a family that is happily looking for someone to toss to the wolves.

By making Marta the central focus of Knives Out, we both empathize with her quest to avoid discovery and get to the truth of what actually happened. This is a Whodunnit of course, so Marta’s actual innocence is a surprise to everyone, including herself. Instead, Johnson uses Marta as a way to highlight the class disparity between her and the Thrombeys. They don’t initially see her as a threat (they don’t know what country she’s from) until she inherits the wealth they believe they are entitled to, but did nothing to earn.

Knives Out (2019)

Knives Out’s use of the Whodunnit to explore the hypocrisy of the wealthy elite is well documented and its success is due to its cast being able to play said pretentious elites so beautifully. By choosing to predominantly focus on the one person who stands outside of that group, Johnson hammers that point home by giving our hero her victory and the ones who fought against her the bitter justice they deserve. Johnson not only uses his ensemble to not only tell an engaging mystery but also to illustrate a larger message.

The Scene of the Crime

The Last of Sheila (1973)

Locations in a Whodunnit are essential to providing the gravitational center to the characters around them. The home base of the Whodunnit, the scene of the crime, is a must with each mystery. It doesn’t always have to be confined, but it needs a center to hold it all together. From the steam train to the riverboat, to the classic old mansion, there’s always somewhere where everyone is rounded up to. After all, you have to gather everyone in the parlor room somewhere, right?

The Last of Sheila is able to break the barriers of the Whodunnit location conundrum while still adhering to its rules. It sets itself to be this mysterious trip down the Mediterranean turned deadly, our suspects hop to many locations, but make no mistake. While this cabal of old show business friends hops from port to port gathering clues, they always return to the same place: their yacht.

The Last of Sheila’s use of its titular ship’s function as an anchor for the film’s mystery to incredible effect. Even as our characters go shoreside to look for clues and understand the central scavenger hunt that kicks the story off, they always return to the ship that brought them all there, to begin with. Putting the characters on a boat forces the isolation of the group itself from the rest of the outside world.

The boat, named “Sheila” after the character we see meet their tragic end at the beginning of the movie, presents not only a home base but also as a constant reminder of the one member of the group who is absent. Sheila’s presence lingers over the characters as their guilt compounds over the course of the game and the pressure keeps rising. It serves not only as its setting for the present, but a reminder of the past that broke these friends apart.

“Squeeze in close or you’ll be out of the picture… and I don’t mean this one.”

A lot of Whodunnits make the choice to confine their characters in a single space, forcing them to work on finding the culprit and saving themselves before they’re next. In The Last of Sheila, it allows the characters to not only focus on the central mystery their host has given them, but also to snipe acidic barbs at each other within spitting distance. As our Hollywood crew might say, location is everything, and Last of Sheila’s case, oftentimes the location is truly the key that unlocks the whole story.

An Inspector Calls

Peter Ustinov’s Hercule Poirot in Death on the Nile (1978)

One of the hallmark elements of a Whodunnit is the arrival of the one individual who is oftentimes unconnected from the other characters, but swoops in and solves the case. Whether they are an official officer of the law, a private investigator, or someone in the wrong place at the wrong time, there’s usually the audience surrogate to take us on that journey. From Sherlock Holmes to Ms. Marple, to Benoit Blanc, the inspector is a classic, though not always necessary, ingredient of the Whodunnit.

The oft most adapted detective of the Whodunnit is Agatha Christie’s Hercule “Please Don’t Call Me French” Poirot. One of Christie’s most beloved characters, Poirot is a blueprint of the Whodunnit detective: always curious, hears everything, and leaves no stone unturned. His investigative style is one of bemusement and his enduring popularity is due to the construction of his mysteries as a chance to fully let the audience in on the fun.

It’s beautifully realized in Death on the Nile, the second of the original 1970s big-screen Christie adaptations and the first to feature Peter Ustinov. In this tale, Poirot is invited to a river cruise on the S.S. Karnak by wealthy heiress Linnet Ridgeway to scare off her former best friend Jacqueline “Jackie” de Bellefort following Ridgeway’s marriage to Jackie’s former fiancé Simon. While Poirot refuses to accept such a personal matter, things become embroiled quickly when she is found murdered.

Poirot snaps into action, playing the hits of the deductive process of Whodunnits. He gradually accuses everyone on the S.S. Karnak, each time presenting plausible motivations for their guilt. Poirot’s process is one of slow manipulation and methodical trickery. As he continues to gather clues and make everyone else nervous, it means the real killer will start to make mistakes. As Poirot himself says in Appointment With Death, “People like to talk, and in talking they tell the truth. But of course, you have to have the genius to listen.”

Poirot’s true skill in representing the detective’s function is how information is presented to us. In Death on the Nile, Poirot is the audience’s eyes and ears throughout the story and there’s no piece of information that Poirot has that is withheld from the audience. Oftentimes the detective is completely unentwined with everyone else but nonetheless tries to find the solution, much like the audience. What they hear, we hear and in Poirot’s case, he hears all. Death on the Nile is smart enough to justify Poirot having the lucky ability to be in the right place at the right time to hear a crucial piece of information. If there’s something Poirot does not see, then neither does the audience.

Always check behind bars for Belgian detectives

What makes Death on the Nile so effective is that it is a mystery that is focused not only on what was said and when, but how it was said and by who. Poirot is the eyes and ears of the audience and he is a cherubic and always curious guide along this string of crimes. It allows the audience to feel like they are conspiring with Poirot to help crack the case. All the pieces are there, leaving it up to the audience to try and put it together before Poirot does, which makes it all part of the fun.

All Will Become Clear…

Clue (1985)

But the most important part of a Whodunnit, as much as the central mystery is that it has to be solved. Even if the characters may not realize it, the audience must. Whodunits have always laid themselves out as cinematic puzzles. The pieces are (mostly) laid out in front of us for the audience to try and put together. As more and more clues are presented, the clearer the whole picture becomes. Nowhere could this be better exemplified in a Whodunnit based on the most beloved mystery game of all time.

When it came time to adapt the iconic board game Clue into a film in 1985, director Jonathan Lyne and writer John Landis were faced with an interesting predicament. Turning a then 40-year-old game into a fully formed story and world. Luckily, they succeeded by using the game’s framework for a classic Whodunnit: porting over everything that it could from its source material. From its colorful characters to its classic manor setting, and in what would cement its eventual cult status, the flexibility of its outcome.

Clue took a unique approach in providing the solution to its Whodunnit by writing, shooting, and releasing three different endings. In the spirit of the game, there are multiple outcomes so that no two viewings were the same. It is a gimmick that is pulled off remarkably well, giving the film lovely rewatch value. After all, just because every Whodunnit has an answer, it doesn’t mean it has to be the same answer.

The purpose of a mystery is to be solved. It’s what brings the people to the theater to begin with. When they invest in a Whodunnit, they are starting a puzzle that they know has a solution. The fun is in finding out. But in order to make it worth the audience’s while and stay true to the genre, you have to give the people what they want. The answer may not necessarily be what they expected, but it will be definitive.

IS this how it happened??

Clue knows this about the genre and its audience and manages to remain true to the game that helped popularize the Whodunnit. The concept of a mystery having several solutions also lies at the heart of the Whodunnit as multiple suspects have viable motives for committing the crime. Clue manages to have its cake and eat it too, offering a host of options that will satisfy one half of a group one night, but then satisfy the other group the next. It’s what makes the game and the film such enduring icons. While justice may not always be served, the mystery will always be solved.

As we sit on the crest of a Whodunnit wave right now, it always makes one wonder what others came before it. But in order to uncover the gems, it helps to clearly define what it is we’re looking for. After all, how are we expected to figure it out without exploring the right clues, questioning the right witnesses, and gathering all in front of the screen to uncover the results?

In my research of the Whodunnit, I had to watch many. Some were old standards, some were hidden gems, and others are ones that may not traditionally be considered one, but are worth bringing up. They are compiled here for anyone who wishes to set off on a mystery.



McKegg Collins

Part time writer, full time nerd