Fantastic Fest 2021 Review: 'Let The Wrong One In' is the silliest of bloodsucker comedies

Conor McMahon’s 'Let The Wrong One In' tests the bonds of brotherly love as one sibling becomes a vampire.

Blood is spilled in 'Let The Wrong One In.'
(Image: © Fantastic Fest)

What to Watch Verdict

'Let The Wrong One In' is the right choice for vampire comedy fans who seek lighthearted, easily digestible subgenre gags, which are—a disclaimer—mostly what this mindless midnighter has to offer.


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    🧄 Knows what it is.

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    🧄 Never wavers in terms of comedy.

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    🧄 Homely but confident and committed.


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    🧄 Rough around technical edges.

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    🧄 Is only of value to comedy fans.

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    🧄 Runs overlong.

A horror-comedy like Conor McMahon’s Let The Wrong One In doesn't exist to be watched solo. The millisecond credits rolled on this slyly titled vampire slapstickery, I felt robbed since I’m covering Fantastic Fest 2021 remotely. In a better national situation, sans pandemic, I’d be in Austin sipping a hoppy Electric Jellyfish in an Alamo Drafthouse theater, belly-laughing with a crowd at the harmless hilarity of McMahon’s bloodsucker buffoonery. Instead, after watching a screening link Chromecast'ed to my television (inside baseball), my reaction was concise: “I wish I watched Let The Wrong One In with a bunch of like-minded maniacs.” What McMahon lacks in funded freedoms and rather unpolished craftsmanship he redeems through a series of cheeky, punny, big-dumb comedy swings that somewhat endear the mega-low budget luster.

One morning during breakfast, teenage Matt’s (Karl Rice) deadbeat brother Deco (Eoin Duffy) raps on the window in discomfort and duress—outside their disapproving mother’s (Hilda Fay) earshot. Deco’s flesh is burning, and he complains of an unquenchable hunger. Matt thrusts Deco in front of their dining room mirror, and much to Deco’s displeasure, his reflection doesn’t appear. Deco’s nightlife irresponsibility meets the direst of consequences after a lavatory hookup with an anonymous bride since fang marks weren’t just an inebriated kink—Deco’s now a vampire, which is just one more way for the loser to suck.

McMahon’s approach seems to roll with punches brought on by COVID-19 restrictions and monetary shortcomings. Actors continually struggle to annunciate past obtrusive fang molds, which becomes an acknowledgment joke in Deco’s dialogue about the ongoing speech impediment. Gore effects are meltaway claymation influenced by Sam Raimi’s deadite disintegration in Evil Dead, rationed for a backloaded finale. Purists will poke holes in McMahon’s vampiric attributes the way umbrellas provide adequate sunlight protection. Some might remark how Franz Ferdinand or Violent Femmes licensing rights represent the lion’s share of production spend. That’s the experience’s signature quirk (and eventual charm) once Let The Wrong One In aligns Deco and Matt’s brotherly quarrel with a vampire hunter named Henry played by Rupert Giles himself, Anthony Head, and his vampire wife’s crusade to drain, transform, and eradicate humanity. It’s more than just slapdash animal CGI and a lack of skin-blistering effects—it’s fart jokes as Deco fails his bat morph and nonsense montages of Deco galavanting through public parks while eating blood-drizzled soft serve cones.

If you’re not a horror-comedy fan, Let The Wrong One In will be more disappointing than Taylor Lautner’s career after Twilight. There’s nothing revolutionary about vampiric lore, nor does McMahon’s presentation elevate beyond backyard vampire cosplay and digital camcorders (the vibe). You’re watching Let The Wrong One In because countess Sheila (Mary Murray) uses a severed cabbie’s head as her gang's bloody-nose drink dispenser, or for Deco’s rubber kitchen glove sashay as Eoin Duffy oversells Deco’s “lowlife in rebound” arc amidst commonplace vampire gags (feeding frenzies, hovering on ceilings, etc). The appeal to Let The Wrong One In is how uninterested McMahon seems about furthering any sense of vampire mythology—we're here to erect nightclubs that look like Party City Halloween aisles and let Buffy The Vampire Slayer obsessors nerd out over Giles teaching Matt about his sandalwood stake skills.

Even at that, there’s a juvenility to Let The Wrong One In that’s lowest-brow humor. Hence my recommendation for viewing parties where gatherers can guffaw and spread infectious laughter. Fight choreography is often ridiculous—Henry crashes through bathroom drywall like the Kool-Aid Man without pause—and levitation or hosting effects, Deco lifting Matt by the ankles with one hand, respect the dangly magic of pulley systems. When McMahon’s special effects team finally works their gruesome talents, Matt paddles exposed hearts with home run swings and hoses spray red liquids all over outfits, houses, sheds, or wherever else bodily gore splats. No actor shackles themselves to dramatic integrity as Anthony Head steals a referential Jack Torrance nod. Karl Rice uses his chips n’ garlic sauce breath to repel vampire aggression, or characters giggle as they fly around metropolitan skyscapes (aka noticeable green screens). Mr. McMahon has created one of the least serious vampiric tales I’ve ever beheld, and that’s not an executioner’s final judgment.

Let The Wrong One In yucks it up harder than Goofy on laughing gas and attempts an overarching metaphor about how Deco’s habits were bleeding everyone he loves dry years before Shelia passed her disease. It’s a far cry from poignant and prolific, but that’s fine because everyone’s committed to Conor McMahon’s undead playfulness no matter how monumentally silly. From an inflatable penis in Transylvania to a vampire critter that serves as a cherry on this syrupy, saccharine horror-comedy sundae, Let The Wrong One In is an artfully lacking but charmingly spunky midnight cinema snack. Maybe not a Reese’s peanut butter cup, but the less uniform general store equivalent made from scratch by the saintly owners and wrapped in see-through plastic—there’s always something more delicious about products produced with love. As sappy as that sounds, it’s why I’m recommending Let The Wrong One In.

Matt Donato

Matt Donato is a Rotten Tomatoes approved film critic who stays up too late typing words for What To Watch, IGN, Paste, Bloody Disgusting, Fangoria and countless other publications. He is a member of Critics Choice and co-hosts a weekly livestream with Perri Nemiroff called the Merri Hour. You probably shouldn't feed him after midnight, just to be safe.