Spoilers for Knives Out follow.
Murder mysteries usually revolve around hatred, or jealousy, or any number of negative states of mind. That might seem a bit obvious - they’re mysteries about murder, after all, and murder tends to be driven by negative emotions when it occurs in real life. Thus, solutions to murder mysteries typically emerge as the detective uncovers the killer’s homicidal motive, and the big drawing-room reveal tends to be followed by the accused lashing out with previously-concealed fury. The point is: the case is solved through identifying the bad guys.
Except Knives Out. Knives Out’s mystery hinges on kindness.
For a murder mystery, Knives Out tells us exactly what happened surprisingly early in the piece. In the time it takes for detective Benoit Blanc to flip a coin, we get a full rundown of all the events immediately surrounding Harlan Thrombey’s death, through the eyes of the “killer,” Harlan’s nurse Marta. Sure, Chris Evans’ sweater-clad character Ransom is later revealed to have killer intent, but that isn’t precisely why Harlan dies. As it shakes out, Ransom’s plan is defined by its failure. It leads to another outcome entirely wherein Harlan took his own life instead, while Marta believes she accidentally killed him via overdose.
To begin with, that’s a structural inversion of the mystery genre shared by few titles, save for a handful that directly inspired the film. Marta is the “killer,” yet she gets away with it, and also didn’t kill anyone, despite thinking she did. The would-be murderer also didn’t kill anyone, but thinks he did, and eventually starts attempting to solve the mystery alongside the detective. In the end, the collar is based on attempted murder, not an actual murder. Harlan Thrombey killed himself, two people in his life think they killed him, and only one of those people wanted him dead. That’s the “what.” But Knives Out is about the “why,” and that’s where the film’s most subtle and delightful genre subversion lies. Or rather: tells the truth.
Early in the film, detective Blanc asks Marta if being kind-hearted makes her a better nurse. That Blanc leads with that question brings up an interesting and unique aspect of both Knives Out and the two characters in question. From the very beginning, Blanc accepts Marta’s kindness as an immovable fact of the case - likely due in part to her inability to lie without vomiting, but also through his developed and astute judge of character. It’s novel, and almost corny, that Marta physically can’t lie, but it’s played so devoid of cynicism that we accept it. After all, Blanc does, and it is Marta's goodness and skill at her job that brings him to unravel the mystery at all.
Marta certainly follows through on the traits with which Blanc endows her. Among those in Harlan’s orbit, she’s the only person who actually cares about him. His family members see him as an exploitable meal ticket in life, and a potential inheritance payout in death. Marta, on the other hand, doesn’t have skin in the game. She doesn’t expect an inheritance. She doesn’t play anybody against anyone else. She’s just kind to Harlan, thus becoming his only confessor and confidant. When she realises (albeit incorrectly) that she’s mistaken his medicine for his morphine, we’re absolutely heartbroken - not for Harlan, but for distraught, impotent Marta. Ana de Armas’ performance draws us in that intuitively.
It’s little surprise Blanc becomes Marta’s best ally. Blanc makes a huge deal out of her innate goodness, thrilled to find such a person after a career dealing with dastardly deeds. He’s not only the sole character to properly respect Marta; he’s the only one who sees her kindness as anything other than a weakness. At one point or another, every Thrombey seeks to exploit her honesty and generosity - even, arguably, Harlan - but Blanc is simply fascinated by her. To someone so obsessed with the truth, a person who physically cannot tell a lie must seem like the most wonderful person on Earth.
Perhaps Blanc is so impressed by Marta’s capacity for good because it’s something everyone else seems to lack. The Thrombeys are a selfish, treacherous bunch, out to get each other as much as to get Harlan’s money. Much has been made of the film’s Trump-era discourse - notably Don Johnson’s anti-immigrant rhetoric and Jaeden Martell’s alt-right troll - but even the self-consciously “woke” Thrombeys are deeply self-centred and cruel on a personal level. Though Marta’s kindness contrasts with the Trumpism that would have her deported, it’s also a virtue in its own right. That’s particularly true in the aggressively antagonistic atmosphere of 2019, but it’d be true anytime. Goodness is a rarity, and it must be treasured and protected.
Ultimately, the “why” of Harlan Thrombey’s death turns out, uniquely, to be a case of financially-driven murderous intent foiled by instinctual professionalism and a desire to die with dignity. It’s a strange confluence of events, and a strangely optimistic one. That Marta emerges with an enormous inheritance is beside the point: she also comes away with a clean conscience and a future. Maybe there’s hope for us yet.
Knives Out mostly subverts its genre in subtle ways, letting its well-told mystery do the heavy lifting. Thematically, though, it swerves away from the negativity that tends to fill these stories, towards its surprise protagonist. That subtle shift can be found in Rian Johnson’s last couple films: Looper closed with its protagonist choosing to remove his own violent influence from the world, while Star Wars: The Last Jedi ended up presenting a surprisingly pacifistic worldview for a movie with “wars” in the title. There are many ways to subvert the murder mystery genre, but when the big twist is someone being a good person who’s good at their job? That’s special.
You don’t often associate murder with kindness. Death and kindness, on the other hand, are slightly less foreign to one another - especially when you get into the grey, assisted-suicide-adjacent realm this film flirts with. Perhaps that’s why Knives Out feels so fresh. Somehow, despite all the backstabbing, it could be the most unexpectedly wholesome murder mystery ever put to screen.