What Is The Plot Twist In 'Arsenic And Old Lace'?

The plot twist in 'Arsenic and Old Lace' hits like a ton of bricks when you realize the sweet, elderly Brewster sisters are actually serial killers who poison their elderly boarders as a twisted act of charity. Their nephew Mortimer, a theater critic who thinks he’s the only sane one in the family, stumbles onto their dark secret while dealing with his own chaotic relatives—like his brother who thinks he’s Teddy Roosevelt. The real kicker? The aunts see their murders as merciful, believing they’re saving lonely old men from suffering. The play’s dark humor shines when Mortimer, desperate to protect them, spirals into panic while the bodies pile up in the basement. It’s a brilliant subversion of the 'harmless old lady' trope, mixing horror and comedy in a way that leaves you equal parts shocked and laughing.

Let me break down the genius of 'Arsenic and Old Lace’s' twist. The Brewster sisters, Abby and Martha, seem like pillars of kindness—baking pies, serving elderberry wine, and doting on their nephews. But their cozy home hides a gruesome secret: they’ve been murdering lonely old men by spiking their wine with arsenic, strychnine, and 'just a pinch' of cyanide. The brilliance lies in how casually the reveal unfolds. Mortimer discovers a body in the window seat, assuming it’s his unstable brother Jonathan’s work, only to learn his aunts are the real culprits.

What makes this twist unforgettable is the sisters’ rationale. They genuinely believe they’re doing good, offering a peaceful end to those with 'no relatives or friends.' Their cheerful indifference to the murders contrasts hilariously with Mortimer’s escalating hysteria. Meanwhile, Jonathan—a actual criminal with a surgically altered face—becomes almost comically secondary to their crimes. The play twists further when Teddy, another brother who believes he’s President Roosevelt, happily buries the victims in the basement, thinking they’re yellow fever casualties from the Panama Canal. The layers of absurdity make the darkness funnier, and vice versa.

The final irony? Mortimer, terrified he’s inherited the family madness, proposes to Elaine in a frenzied panic, only to learn he’s technically not a Brewster by blood. The play’s twist isn’t just about murder—it’s about confronting the madness we pretend isn’t there, wrapped in a farce so sharp it still cuts decades later.

Here’s why 'Arsenic and Old Lace' sticks with you: it takes gothic horror tropes and flips them into comedy gold. The Brewster aunts aren’t just eccentric—they’re prolific killers with a body count that would make Dexter blush. The twist isn’t just their crimes; it’s how the play treats them. Unlike typical murder mysteries, the thrill comes from Mortimer’s desperate attempts to cover for his aunts while dealing with his brother Jonathan, a literal monster with a face like Frankenstein’s creation.

What’s clever is the parallel insanity. Teddy’s delusion mirrors the aunts’ warped morality, making the whole family weirdly sympathetic. Even Jonathan, the 'villain,' gets upstaged by his aunts’ cheerful homicides. The play’s humor comes from contrast: the aunts discuss poison like it’s a recipe ingredient, while Mortimer’s sanity unravels in real time. The ultimate irony? The police dismiss his warnings because the Brewster ladies are so 'respectable.' It’s a darkly funny critique of how society overlooks evil hiding in plain sight.