Picture a Norman Rockwell painting, one of those snapshots of reassuring, saccharine American normality, and then imagine the Marx Brothers, armed with buckets of black paint and scalpels, gleefully vandalizing it in a fit of Dadaist rage. The result of this iconoclastic assault on the collective imagination would look a lot like "Arsenic and Old Lace," the most anomalous, unhinged, and deliciously macabre creature ever to emerge from Frank Capra’s forge. Yes, that Frank Capra, the bard of the common man, the architect of "Capra-corn," the man who built monuments to optimism like It's a Wonderful Life and Mr. Smith Goes to Washington. Here, Capra takes his America, the one of pristine porches and apple pies, and sits it down in an electric chair for a session of shock therapy, giving us one of the most perfect and funereal black comedies in cinema history.

The film, shot in 1941 but held back in the Warner Bros. vaults until 1944 so as not to kill the golden goose that was Joseph Kesselring’s eponymous Broadway play, is a clockwork mechanism of rare precision. Its genius lies in a semantic and tonal short-circuit that runs through every single frame. Everything in the Brewster sisters’ Brooklyn home exudes Victorian respectability: the embroidered doilies, the tea service, the whispered pleasantries. And yet, it is precisely in this sanctuary of bourgeois normality that a madness as seraphic as it is lethal lies nested. Aunts Abby and Martha are not merely amiable spinsters; they are angels of death who, out of a misguided sense of Christian charity, "help" lonely old gentlemen find eternal peace with a cocktail of elderberry wine, arsenic, strychnine, and "just a pinch of cyanide."

The Brewster house thus becomes a Gothic microcosm worthy of Edgar Allan Poe, if only Poe had written his stories after a binge on laughing gas. The cellar, where nephew Teddy (convinced he is Theodore Roosevelt) ceaselessly digs the "Panama Canal" to bury the victims of "yellow fever," is a literal and metaphorical descent into the unsettling underworld of the family psyche. The claustrophobia of the unity of place and time, a holdover from its stage origins, is not a limitation but a particle accelerator of comedy. Capra transforms the bourgeois living room into a nuclear reactor of neuroses, where every entrance and exit triggers a new, unpredictable fission of chaos.

At the center of this domestic madhouse writhes Mortimer Brewster, played by a Cary Grant who offers one of the most courageous and debated performances of his career. Light-years away from his usual, polished nonchalance, the Grant of this film is a haywire seismograph registering every tremor of the absurd. His reactions are exaggerated, his eyes seem to pop from their sockets, his body contorts in a pantomime of pure panic. Grant himself, in retrospect, criticized his own performance as excessive. He was wrong. His "overacting" is, in fact, a stroke of stylistic genius: Mortimer is our surrogate, the sole shred of (admittedly precarious) rationality thrown into a universe that has abolished the laws of logic. His performance isn’t over the top; it’s the only top there is when the musical staff of reality has shattered into pieces. Through his mounting disbelief, we the audience measure the dizzying deviance of the situation. He is the man of the theatre, the drama critic who detests artifice, hurled headlong into the most incredible of farces and forced to become both actor and director of a drama he did not write.

The film operates on an exquisitely nerdy, metatextual level. The arrival of the outcast brother, Jonathan Brewster, is a masterstroke. His face, crudely stitched up by the alcoholic surgeon Dr. Einstein (a Peter Lorre who looks like he’s escaped from a Fritz Lang film), bears a sinister resemblance to Boris Karloff. The fact that on Broadway the role of Jonathan was played by Boris Karloff himself creates a dizzying hall-of-mirrors effect, a cinephilic wink that shatters the fourth wall. "Arsenic and Old Lace" is not just a comedy of horrors; it is a comedy about the mechanics of horror. Jonathan is archetypal Evil, the kind straight out of a Universal monster movie, who returns home only to discover, to his supreme disappointment, that he’s been outdone in the murder game by his sweet, amateur aunts. His tangible, almost cartoonish menace pales in comparison to the placid, incomprehensible monstrosity of normality.

It is here that Capra subverts himself and the American Dream. The family, the foundational nucleus of his poetics, reveals itself to be a den of hereditary madness. The danger comes not from without—from the cynicism of politics or the ruthlessness of capital—but from within, from the living room, from the loving gesture of offering a glass of wine. The Brewster aunts, played with sublime and chilling candor by Josephine Hull and Jean Adair (both from the original Broadway cast), embody a form of Evil all the more terrifying for being unconscious, cloaked in good intentions. Their homicidal pragmatism is a warped, hyperbolic version of Puritan charity, an extreme consequence of the ethic of caring for one’s neighbor. This chasm between intention and action, between appearance and substance, is the engine of a comedy that leaves a bitter, almost philosophical aftertaste, anticipating Ionesco’s Theatre of the Absurd by a decade.

Contextualizing the film is essential. Made as the world was plunging into the madness of the Second World War, "Arsenic and Old Lace" offers a unique form of catharsis. The global, incomprehensible, and terrifying madness is domesticated, confined within the walls of a Brooklyn home and rendered hilarious. Horror becomes farce, death a running gag. In an era that saw the triumph of state-sanctioned violence, the film proposes a private, almost artisanal violence, and demonstrates its intrinsic absurdity. It is a collective exorcism through laughter, a way of looking into the abyss and finding it comically furnished with Chippendale.

The screenplay by the Epstein brothers, who had already worked the miracle of Casablanca, is a Swiss watch of a script that never misses a beat, a percussive dialogue that builds a crescendo of panic and complications with the precision of a Bach fugue. Capra’s direction, seemingly invisible and functional, is in fact a masterpiece of tonal control. He never yields to the temptation to underline a gag or wink at the audience. He films the inconceivable with the same placidness with which he would have filmed a tenants' meeting, and it is precisely this directorial deadpan that makes it all exponentially more funny and disturbing.

"Arsenic and Old Lace" remains an unsurpassed summit of black humor, a work that dances with funereal grace on the razor’s edge separating sanity from madness, charity from murder, comedy from tragedy. It is the portrait of an American family that, in its attempt to be exceptionally good, has become exceptionally lethal. A merciless and irresistible allegory that reminds us that, sometimes, the darkest cellar isn’t the one down the stairs, but the one hidden behind the most reassuring smile and a perfectly starched doily. A masterpiece that never ages, just like the Brewster aunts’ elderberry wine. The difference being that this, thankfully, can be enjoyed with no side effects. Or almost none.