'Mousetrap' turns Korean folktale into Netflix thriller

The stolen-identity thriller "Mousetrap" is officially primed for its global Netflix debut.

The webtoon-based series follows Moon-jae (Ryu Jun-yeol), a novelist who loses his name, face and life to a mysterious entity known as "the Rat." He teams up with No-ja (Sul Kyung-gu), a loan shark, and Sun-yong (Lee Kyu-hyung), a detective, embarking on a high-stakes hunt to uncover the identity of the Rat.

Helmed by director Kim Hong-sun, who was acclaimed for stylized action and tension in the Netflix series “Dear Hongrang” (2025) and hit dramas “The Guest” (2018) and “Voice” (2017), the drama is inspired by the classic Korean folktale premise that "a rat becomes human after eating fingernails," promising to deliver psychological dread alongside genre-thriller suspense.

"The work is motivated by the folktale of the fingernail-eating rat. It is a thriller about a man whose life has been stolen trying to reclaim his identity," director Kim introduced the drama during a press conference at Hotel Naru Seoul - MGallery in Mapo District, Seoul, Thursday.

Kim added that the webtoon script immediately drew him in. "The original webtoon had a chilling sense of horror, and our writer adapted it dynamically into a chase format. Reading the script, I resonated with Moon-jae's emotions. I just wanted to see who the Rat was, so there was no reason not to direct it," he added.

The cast cited the fast-paced narrative and gripping premise as their primary reasons for joining the project.

Ryu said he found the setup fascinating. "I remembered reading the original folktale as a child. Adapting that story for global audiences appealed to me, and the script raised so many questions that I voluntarily looked up the original webtoon," he said.

Sul noted that the script stood out among the projects he was considering. "There are no supernatural powers or spiritual elements here, just characters who seem somehow incomplete. The sense of immersion as they hunt for the truth was incredible," he said.

When asked what would make the show different from a series with similar themes, the director pointed to its structure. "There are certainly shared themes, but 'Mousetrap' pivots into a relentless chase. We start from a similar premise, but the execution takes a completely different path. The real thrill lies in the cat-and-mouse game of unmasking the imposter. That psychological tension was our primary focus throughout filming and directing," he said.

Ryu plays Moon-jae, a writer who loses everything overnight. Describing him as a novelist who lived in isolation from the world for three years, he said, "When his life is suddenly stolen by an unknown entity, he fights to get it back."

Marking the first dual role of his career, Ryu carefully calibrated his performance to differentiate the two characters. "Since I am portraying both individuals, I focused on subtle adjustments in personality and gaze. Primary emphasis was placed on voice tone so viewers could immediately tell them apart," he said.

Describing his character, No-ja, Sul painted a picture of a fading era. "Think of him as part of the last generation of classic mobsters — a midlevel boss type," Sul explained. "He doesn't care about personal connections or who anyone is. If he’s told to bury someone, he buries them, takes his cut and moves on."

Kim pointed to a single thematic line as the anchor of the series. "There’s a dialogue in the show that says 'life is like an island' and I think that line sums up the entire drama," Kim said. "Each character drifts through the narrative isolated like a lone island. Keeping that sense of detachment in mind will make the viewing experience all the more compelling."

“Mousetrap" premieres globally on Netflix on Aug. 28.