Netflix's Mousetrap: The Folktale Behind the Identity-Theft Thriller

What happened

On 31 July 2026 Netflix confirmed that Mousetrap — Korean title 들쥐 (Deuljwi, “field mouse”) — will premiere on 28 August 2026, and released a teaser poster and teaser trailer. The ten-episode mystery thriller is directed by Kim Hong-sun, whose credits include Voice, The Guest, Money Heist: Korea – Joint Economic Area and Dear Hongrang, and written by Lee Jae-gon (Special Affairs Team TEN, A Model Family). It adapts the Kakao webtoon Field Mouse (들쥐) by Ludovico.

Ryu Jun-yeol plays Moon-jae, a reclusive novelist who writes under a pen name and has not left home in years. In the teaser his fingerprint fails to open his mobile banking app, his passwords stop working and his money and his name slip away one by one; the figure behind it calls himself “The Rat”. To get his life back Moon-jae joins forces with Noja (Sul Kyung-gu), a loan shark who has been chasing him for an unpaid debt, while detective Sun-yong (Lee Kyoo-hyung) pursues The Rat from the other side. Netflix’s title page rates the series 19+ and files it under Thriller and Mysteries.

The teaser poster sets the stakes in one line — “Prove I’m real, or I’m the imposter”, or in Korean “증명하지 못하면 내가 가짜가 된다” — and the trailer ends with The Rat’s voice asking “내가 누구게? 궁금하지?” (“Who am I? Curious?”).

Why is it trending?

The run-up has been dense. On 5 August Netflix released character stills showing Moon-jae in confusion, Noja holding an iron bar and Sun-yong examining documents; Kim Hong-sun called Sul Kyung-gu an exceptionally talented actor perfectly suited to Noja. The official trailer, “Mousetrap | Official Trailer | Netflix [ENG SUB]”, went up on the Netflix K-Content YouTube channel on 13 August (US Pacific time) and showed 101,519 views on 26 August.

On 20 August the cast and director held a production press conference at Hotel Naru Seoul MGallery in Mapo-gu, Seoul. Sul Kyung-gu said the script was the most entertaining he had read at the time and that the series has neither heroes nor supernatural powers; Ryu Jun-yeol said he was drawn by a modern reinterpretation of a folktale he had known since childhood meeting a global audience; Lee Kyoo-hyung said the idea that someone could take over your life in a society overflowing with personal data gave him chills; Kim Hong-sun said the webtoon’s chilling horror had been reshaped into a dynamic chase. Sul also described the action scenes: Ryu’s character would faint or be shot and lie there while Sul finished the stunts — a choice Ryu said he had asked the director for, adding that he felt sorry his senior handled everything.

The pairing itself is the headline. The Week noted on 25 August that Mousetrap is the first collaboration between Ryu Jun-yeol and Sul Kyung-gu, and traced both careers: Ryu’s breakout was Reply 1988 (2015–2016), which earned him a Baeksang Arts Award, followed by A Taxi Driver (2017) opposite Song Kang-ho and the two-part Alienoid; Sul Kyung-gu’s breakthrough came in Lee Chang-dong’s Peppermint Candy (1999), and he also starred in Oasis (2002). The South China Morning Post’s review arrived on 26 August: Pierce Conran called the series slick but sluggish, enigmatic if slow-moving, and placed it in Netflix Korea’s run of daring August releases alongside Mask Girl (2023), The Frog (2024) and Aema (2025).

What you need to know

• Mousetrap (들쥐) premieres on Netflix on 28 August 2026 with ten episodes and a 19+ rating.
• It is directed by Kim Hong-sun (Voice, The Guest, Money Heist: Korea – Joint Economic Area, Dear Hongrang) and written by Lee Jae-gon (Special Affairs Team TEN, A Model Family).
• The source is the Kakao webtoon Field Mouse (들쥐) by Ludovico, whose tagline on Kakao Webtoon is “a man who lived only at home for ten years goes out for the first time in ten years”.
• Ryu Jun-yeol is Moon-jae, a reclusive novelist whose identity is stolen; Sul Kyung-gu is Noja, the loan shark chasing him for an unpaid debt; Lee Kyoo-hyung is detective Sun-yong.
• It is the first time Ryu Jun-yeol and Sul Kyung-gu have worked together.
• Netflix confirmed the date on 31 July 2026, released character stills on 5 August, posted the official trailer on 13 August and held the press conference in Seoul on 20 August.
• The teaser poster’s line is “Prove I’m real, or I’m the imposter”.