A reclusive novelist wakes up one morning and his own fingerprint won’t unlock his phone. His passwords stop working. The one friend who helped him navigate the outside world vanishes. Piece by piece, someone else is living his life, and he has no way left to prove he’s really him. That’s the premise driving Mousetrap, Netflix’s next big Korean thriller, and it’s built on a Korean folktale creepy enough to make the whole thing linger.
Mousetrap At a Glance
- Korean title: 들쥐 (Deuljwi, literally “Field Mouse”); earlier reported in English-language coverage as The Rat
- Genre: Mystery / pursuit thriller, limited series
- Episodes: 10, roughly 50 minutes each, according to KDramaWorlds and AsianWiki
- Release date: August 28, 2026, exclusively on Netflix worldwide (confirmed by Netflix’s own newsroom)
- Director: Kim Hong-sun (Dear Hongrang, Money Heist: Korea – Joint Economic Area)
- Based on: The webtoon Field Mouse by Ludvico, serialized on Daum Webtoon from 2017 to 2020
- Cast: Ryu Jun-yeol, Sul Kyung-gu, Lee Kyu-hyung
- Filming locations: Not publicly confirmed yet (see below)
Watch the Official Teaser
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What Is Mousetrap About?
Ryu Jun-yeol plays Moon-jae, a novelist who writes under a pen name and hasn’t left his house in years, living the same quiet routine every day. Then his identity starts unraveling: fingerprint authentication fails, passwords stop working, and the connections that prove he’s himself slip away one by one. Someone calling himself “the Rat” has taken his name, his money, and his life, and seems to know exactly who Moon-jae is. Stripped of everything, Moon-jae sets out to hunt the Rat down, according to the official synopsis from Netflix.
That search pulls in two more people. No-ja (Sul Kyung-gu) is a loan shark and part-time private investigator who’s been tracking Moon-jae for money owed since he vanished three years earlier. When Moon-jae resurfaces, No-ja gets pulled into the identity case chasing a payday. Sun-yong (Lee Kyu-hyung), a detective, is chasing the Rat too, for reasons the show is keeping close to the chest. Three people, three different motives, one pursuit.
The show’s tagline says it best: “Prove I’m real, or I’m the imposter.”
The Korean Folktale Behind the Title
Here’s the detail most English-language coverage skips over: the Korean title 들쥐 references a much older story. In Korean folklore, if a rat eats a person’s clipped fingernails, it transforms into an exact copy of that person, right down to walking into their house and taking their place while the real person is turned away as the fake. Netflix’s own newsroom leads with this folktale as the “jarring premise” behind the show, which tells you how central it is to the story, not just a title reference.
It’s a genuinely unsettling piece of Korean folk horror, and it maps directly onto Moon-jae’s situation: someone has effectively become him, and the people around him can no longer tell which version is real. If you grew up with the story, the title alone is a spoiler of sorts. If you didn’t, it’s worth knowing going in.
Who’s In the Cast?
Ryu Jun-yeol as Moon-jae
Ryu Jun-yeol leads the series as the reclusive novelist at the center of the mystery. He’s coming off The 8 Show and Revelations for Netflix, and Korean audiences will also know him from Reply 1988, Lucky Romance, and films like Alienoid and A Taxi Driver. Moon-jae is described as living in isolation due to social phobia, which makes the sudden, forced confrontation with the outside world (and with “the Rat”) land even harder.
Sul Kyung-gu as No-ja
Sul Kyung-gu plays No-ja, the loan shark turned reluctant investigator. He’s a Netflix regular too, with Kill Boksoon and Good News on his résumé, plus a long film career including The Book of Fish and Kingmaker. No-ja isn’t chasing justice, he’s chasing his money, which sets up a genuinely uneasy alliance with Moon-jae rather than a straightforward hero-and-sidekick dynamic.
Lee Kyu-hyung as Sun-yong
Lee Kyu-hyung rounds out the trio as Detective Sun-yong. Viewers will recognize him from Prison Playbook and Hi Bye, Mama!. New character stills show him examining a mysterious file, which Soompi notes has already sparked speculation about what exactly landed in his hands, and how his investigation intersects with Moon-jae and No-ja’s.
Who’s Behind the Camera?
Director Kim Hong-sun previously helmed the Netflix Korean drama Dear Hongrang and the heist series Money Heist: Korea – Joint Economic Area, so he’s no stranger to twisty, high-tension plotting. The series is written by Lee Jae-gon and adapts the webtoon Field Mouse by artist Ludvico, which ran on Daum Webtoon (now part of Kakao’s webtoon ecosystem) from February 2017 to April 2020. There’s currently no official English translation of the webtoon, which makes the Netflix adaptation most people’s first exposure to the story.
Filming ran from mid-April to November 2025, according to What’s on Netflix, so the show has been in the can for months ahead of its premiere.
When Can You Watch It?
Mousetrap premieres August 28, 2026, globally on Netflix, all at once as a 10-episode limited series. Note that some earlier reports floated an August 18 date; Netflix’s own newsroom and release calendar confirm August 28 is correct, so mark that date instead.
What About Filming Locations?
Honest answer: nothing official yet. As of this writing, neither Korean nor international outlets have reported confirmed shooting locations for Mousetrap, and no fan-spotted set photos have surfaced either. That’s not unusual this close to a premiere. Production kept a fairly low profile through 2025, and location details for Korean thrillers like this one often only come out once the show airs and viewers start recognizing streets, buildings, or interiors on screen.
We’ll update this article (or publish a dedicated filming-locations guide) once real locations are confirmed, so check back after the August 28 premiere.
FAQ
Is Mousetrap based on a true story?
No. It’s adapted from the webtoon Field Mouse by Ludvico, itself inspired by a Korean folktale about a rat that transforms into a person after eating their fingernails. The premise is fictional, though the underlying identity-theft anxiety feels very real.
How many episodes does Mousetrap have?
10 episodes, reported as a limited series, meaning it’s designed to tell one complete story rather than set up multiple seasons.
Is Mousetrap connected to the play “The Mousetrap” by Agatha Christie?
No. Despite the shared English title, they’re unrelated. The Netflix series’ Korean title 들쥐 (“Field Mouse”) reflects its own folktale roots, not Christie’s work.
Where was Mousetrap filmed?
Not publicly confirmed as of this writing. See the section above, and check back after the show premieres.
When does Mousetrap come out?
August 28, 2026, on Netflix worldwide.
