Mouse

Mouse (2021) is a complex and dark psychological thriller that follows Jung Ba-reum, a steadfast and kindhearted rookie police officer, and Ko Moo-chi, a veteran detective consumed by a vengeful obsession with the serial killer who murdered his family. The narrative is set against a near-future background where a genetic test can identify the 'psychopath gene' in a fetus with 99% accuracy, raising the ethical question of whether potential monsters should be eliminated before birth.

As a series of brutal murders grips the nation, Ba-reum and Moo-chi form an unlikely partnership to track down a predatory serial killer. However, the investigation takes an unprecedented turn after a life-altering encounter that leads to a groundbreaking brain surgery. The story spirals into a deep exploration of identity, as the characters uncover a massive conspiracy involving swapped infants, secret government organizations, and the terrifying realization that the line between a hero and a monster is thinner than anyone dared to imagine.

The core of Mouse lies in the philosophical debate of nature vs. nurture and the definition of true justice. The creators sought to explore a 'fantasy' scenario where a psychopath—traditionally incapable of feeling remorse—is forced to develop a conscience. Through this, the series argues that the ultimate punishment for a monster is not death, but the crushing weight of empathy and the realization of one's own sins. It challenges the viewer to consider if genetic destiny can be overcome and if redemption is possible for the irredeemable.

Critics and audiences have discussed several interpretations of the ending. One common alternative reading is that Ba-reum's 'redemption' is a form of medical determinism rather than true free will—that he only became 'good' because of a physical part of someone else's brain, which raises questions about where the soul resides. Another interpretation focuses on the mouse metaphor, suggesting that even at the end, Ba-reum was just a piece of a larger political experiment, and his 'choice' to confess was exactly what the hidden powers needed to pass their abortion bill. Some viewers also see the ending as a reincarnation metaphor, where Ba-reum's death and the symbolic return of the 'mouse' in the epilogue suggest a never-ending cycle of genetic experimentation.

Mouse made a significant impact on the K-drama landscape by pushing the boundaries of the crime-thriller genre with its R-rating and 'sci-fi' genetic premise. It sparked public discourse in South Korea regarding the ethics of genetic testing and the treatment of psychopaths in the justice system. The series was highly successful for cable network tvN, ranking as one of the top-rated Wednesday-Thursday dramas in the first half of 2021. It is often cited as a 'masterpiece of twists,' influencing subsequent psychological thrillers to adopt more non-linear and unreliable narrator tropes. Lee Seung-gi’s performance, in particular, was widely praised for shattering his 'nation's younger brother' image and establishing him as a top-tier dramatic actor.

The audience reception for Mouse was generally ecstatic but polarized. Most viewers praised the shocking twists and the acting (especially Lee Seung-gi and Lee Hee-jun), calling it one of the most addictive thrillers in years. However, a segment of the audience criticized the plot for being overly convoluted and relying on 'pseudo-science' brain transplants that felt too far-fetched for a grounded crime thriller. The finale was widely regarded as heartbreakingly perfect, providing the emotional closure that many felt was necessary after such a brutal journey. Despite criticisms of its 'hysterical' plotting, it maintained high ratings and a dedicated cult following who spent weeks dissecting theories online.