The Setup

Je Mun-jae used to be a successful TV drama writer, but his success was a fraud from the start. He built his career by stealing scripts from students at the writing academy he ran and publishing them under his own name, and when the plagiarism came to light, he panicked. Around the same time, he was running a shell company under a fake identity for tax evasion, with a subsidiary tucked away in Hong Kong, and had borrowed money from a loan shark named No-ja before skipping out on the debt entirely. Terrified of being caught by both his creditors and the people he'd wronged, he forged documents making it look like he was living abroad and simply stopped leaving his apartment. For ten years he didn't step outside even once, surviving on delivery food, exercising on a treadmill, and following the outside world only through his computer screen.

Ten Years Later

After a decade of this self-imposed exile, he starts noticing something strange: the same small handful of people always seem to be wandering the street below his window, day after day, year after year. Then an old middle-school classmate, Na Seong-gi, mentions offhand that he saw Mun-jae around town recently, which is impossible, since Mun-jae hasn't left his apartment in ten years. Unsettled, Mun-jae finally forces himself outside for the first time in a decade, and that's when he discovers someone else has been living as him. A perfect double has taken over his identity so completely that Mun-jae's own fingerprints and resident registration number no longer match official records, and the real Mun-jae is now the one being hunted by police as a suspected fraud impersonating himself. He later confronts Na Seong-gi, luring him into a garage and beating him once it's clear he'd been helping the double all along.

The Conspiracy Around Him

As he tries to untangle what's happened, Mun-jae discovers his own lawyer and classmate, An Gyeong-hwan (who at one point goes by the alias Yu Tae-hwan), had secretly been helping the outside world on his behalf for years while actually being in league with the double, plotting to erase the real Mun-jae for good. An Gyeong-hwan is the one who arranged to have Mun-jae's own uncle killed, since the uncle had been the double's very first collaborator and knew too much to be allowed to talk. Mun-jae's ex-girlfriend and former writing colleague, Song In-ju, tries to help him investigate and is killed in a car bombing right in front of him. And the loan shark No-ja, it turns out, is a genuinely brutal person capable of dismembering non-paying clients and feeding the remains to dogs, though also strangely clumsy and oddly fixated on someday taking up wild boar hunting for extra cash, circumstances still force him into an uneasy alliance with Mun-jae, since he's one of the few people who actually knows what the real Mun-jae looks like and can't be fooled by the double.

The Field Mouse's House

The double calls himself the Field Mouse, after a Korean folktale about a mouse that eats a person's discarded nail clippings and transforms into an exact copy of them, eventually replacing the real person entirely. He runs a front charity called Field Mouse's House, which is really a shadow network: it identifies people who abuse positions of power, has them killed, steals their identities, and hands those identities to poor or marginalized people it's decided to "save," while quietly continuing to surveil everyone it's supposedly helped. Anyone who gets too close to the truth or refuses to cooperate gets killed by hired assassins, most notably a particularly cold hitman named Kim Sang-su, who does much of the group's dirty work, including eventually shooting No-ja during a confrontation, a wound No-ja doesn't survive. Only after his death is it revealed that "No-ja" wasn't even his real name; he was actually Kim Yeong-geun, and in the epilogue an anonymous package arrives addressed to that real name at his father's house, the only time in the whole story his true identity is used.

The Detective

Meanwhile, a demoted detective and another of Mun-jae's middle-school classmates, Park Sun-yong, gets pulled into the case after a young man connected to Field Mouse's House commits suicide. Park eventually corners the double face to face at the group's headquarters. The double, posing convincingly as the real Mun-jae, almost talks his way out of it by claiming he attended Park's father's funeral, until Park suddenly remembers the real Mun-jae was hospitalized at the time and never could have been there. Park curses him out under his breath and walks away, only to be assassinated shortly after by a hitwoman disguised as a café waitress, set up through a bribed journalist named Hwang Tae-bok, who's arrested for it in the epilogue. Hwang's own arc starts earlier, when he's shown complaining to a drinking buddy about how his journalism career amounted to nothing but being belittled and feeding tips to Park. That drinking buddy turns out to be another victim of the Field Mouse's network, a man secretly living under the stolen identity of an already-murdered tax evader, and it's his drunken confession about being surveilled and living a stolen life that first tips Hwang off to the larger conspiracy, which he then passes to Park.

The Middle-School Incident

The real answer to who the Field Mouse is, and why any of this happened, traces back to Mun-jae's middle school years on a remote island in Jeollanam-do. Back then Mun-jae was part of a school writing club whose members turned on each other over petty humiliations. In one writing assignment, Mun-jae left several club members' names out of what he wrote, trying to stay in his abusive father's good graces after getting caught stealing an adult video from a rental shop, but doing so accidentally exposed everyone's private shames to the entire school, triggering vicious bullying and eventually a near-fatal assault where Mun-jae was struck in the head and hospitalized. For years, Mun-jae assumed a classmate named Han Jung-pil was behind it, since Han had the clearest motive after his mother's real, humiliating occupation got exposed. But when Mun-jae finally visits Han in prison, Han insists he only ever plotted the murder and never went through with it: the "gunshot" Mun-jae remembered was fireworks, the flowerpot that nearly hit his head was made of cardboard. Someone else did the real violence, though Han cryptically insists afterward that he never actually lied. It later comes out that Han really had thrown a rock in anger at a barking dog that day, accidentally killing it, and while burying it in guilt he slipped into the reservoir and, climbing out, witnessed a blood-soaked figure dragging a body away, making him the source of the "reservoir ghost" rumor everyone in town believed for years, a story he spread himself after no one believed what he'd actually seen.

The Writing Club, One by One

Other classmates from the writing club get investigated and cleared one by one, each carrying a hidden tragedy of their own. Park Ji-woong, the quiet, sharp-eyed kid who'd done time in juvenile detention, hadn't committed some serious crime; his grandmother simply couldn't afford the settlement after he got into a fight defending the writing club from the school bully, so he served time instead of paying it off. He reconnects with Mun-jae as an adult, confirms which four classmates plotted against him, and is shot dead by hired hunters not long after. Shin Eu-tteum, who resembled the Field Mouse so closely that he was suspected for a long stretch of the story, turns out to have his own hidden pain: his father wasn't away on a foreign business trip as everyone assumed, but was an undocumented immigrant from Pakistan who got caught gambling, was deported, and started a new family back home, leaving Eu-tteum's mother to raise him alone on a bee farm. Kim Seong-pyo, remembered as a quiet, humorless kid always in and out of hospitals for a supposed rare illness, admits as an adult the illness was a lie; he'd actually spent his childhood being treated for autism and anxiety attacks at a psychiatric facility, and stayed on medication afterward, which got him mocked as a junkie. He resents Mun-jae bitterly for the rumors that dogged him for the rest of school, though he still visits him in the epilogue. Lee Geum-seok, the gentle, endlessly mocked classmate nicknamed "Geum-ja" for his effeminate mannerisms, was gay and secretly involved with another classmate, Hwang Dae-jun, whom Mun-jae once caught him holding hands with near an old bomb shelter the club used to stash money from bootlegged videos. After being outed and pulled into the plot against Mun-jae out of shame and social pressure, Geum-seok was consumed by guilt and fear of being killed to keep him quiet, and eventually jumped to his death at the same reservoir tied to the original incident. Hwang Dae-jun corroborates this years later and even suggests Geum-seok's death might not have been suicide at all, but another hit staged to look like one.

There's also a chilling detail involving a classmate named Kim Min-woo, barely mentioned in passing during flashbacks. He reappears late in the story as the detective who supposedly took over Park Sun-yong's investigation, except Mun-jae realizes with a jolt that this man doesn't match his memory of the real Kim Min-woo, implying the Field Mouse's network had already killed and replaced him too.

Supporting Witnesses

Two adults from Mun-jae's school years become useful sources during the investigation: the caretaker of the school's livestock barn, Shin Yeong-tae, and the caretaker of the shooting range, Kim Chang-hwan, who between them confirm someone unfamiliar had been sneaking around the barn and borrowing bullets from the range around the time of the original assault. A former class prefect, Oh Myo-han, explains the local legend behind the reservoir: townspeople believed a falsely accused, wrongly executed orphan's spirit haunted the reeds near the water whenever a red moon rose, turning anyone who wandered too close into a copy of itself, though she says she never believed the story herself. Another classmate, Go Ju-yong, once saw the Field Mouse's signature tattoo firsthand as a kid and got teased for supposedly being close with a "corpse-obsessed weirdo"; his testimony is what eventually connects the tattooed stranger to the assault on Mun-jae specifically. The writing club's faculty advisor, Oh Cho-hui, had a name that sounds feminine in Korean but was actually a middle-aged bachelor teacher the boys avoided because of his smell; Mun-jae only joined the club because Han Jung-pil lied and told him the advisor was a beautiful woman. And a delinquent senior, Shin Hae-seok, tough enough to beat up the school's athletes, once returned from a hospital stay to savagely attack the writing club without warning, until Park Ji-woong fought back and drove him off for good.

The True Identity of the Field Mouse

The real culprit behind everything turns out to be Oh Gi-wan, a troubled transfer student from the same writing club who everyone assumed had died years earlier. What witnesses actually saw back then wasn't Oh Gi-wan's body; it was his abusive adoptive father's corpse, dressed in a school uniform and burned past recognition, which the other boys mistook for Oh Gi-wan himself. In reality, Oh Gi-wan had killed that man and burned down the house, then disappeared, officially recorded not as dead but as missing.

Oh Gi-wan's Past

The full and much darker backstory comes out in the story's final act. Oh Gi-wan had actually been adopted into Mun-jae's own family before Mun-jae was even born. Once the biological son arrived, Oh Gi-wan lost his parents' attention entirely and was eventually abandoned outright by Mun-jae's father at a place called Sotae Recreation Area, which is also the origin of the strange tattoo on the double's arm, referencing that exact site and year. After being abandoned there as a small child, Oh Gi-wan was taken in by another man who trafficked him for street begging and subjected him to years of severe physical and sexual abuse, leaving him so emotionally numb he could no longer feel sadness at all.

Years later, when Oh Gi-wan happened to see Mun-jae's father again and read the account Mun-jae had written for that fateful class assignment describing his own childhood abandonment, all of Oh Gi-wan's buried trauma resurfaced at once. He traveled back to Sotae Recreation Area, the very place he himself had been abandoned as a child, and the emotional collapse that followed drove him to beat Mun-jae nearly to death right there, the real assault behind everything, distinct from Han Jung-pil's abandoned, never-executed plan. He then went home, killed the man who'd abused him for years, and burned the house down, erasing his identity completely.

Having grown up watching poor, forgotten people die utterly alone with no one left to remember them, Oh Gi-wan built his entire identity-theft network years later around the idea of giving people like that new lives and new names, even though the way he went about it was steeped in murder, and even though the people he "saved" were kept under constant surveillance by his own people, undercutting the ideals he claimed to believe in. His visible charity work and the welfare facilities he built were assumed by everyone, including the readers, to be a smokescreen for his crimes, but the final chapter makes clear his desire to help really was sincere, however monstrous the methods.

The Final Confrontation

Everything comes to a head back at Sotae Recreation Area, where Mun-jae and No-ja finally corner him. In the struggle, Oh Gi-wan lures Mun-jae toward the site's entrance, and Mun-jae ends up shooting him. As he lies dying, Oh Gi-wan asks how it's possible for a person to see themselves inside someone else's memory, hinting at the story's final gut-punch: the crying, abandoned child Mun-jae had always remembered as a childhood image of himself was, all along, a memory of young Oh Gi-wan. Because Oh Gi-wan had no legal existence, no family, and almost no one left who remembered him as a person, his body is cremated unclaimed, mourned only by Mun-jae and two old writing-club classmates, Eu-tteum and Seong-pyo.

Epilogue

Mun-jae publicly admits to the plagiarism that started the entire chain of events, returns all the money he profited from it to the students he stole from, and begins writing a new, presumably honest novel titled 없는 사람들 ("People Who Don't Exist"). Detective Gu Rapa-illeo, who took over the investigation after Park Sun-yong's death, visits to thank Mun-jae for his cooperation; Gu Rapa-illeo has his own backstory as a once-promising criminal profiler demoted to forensics after being branded a conspiracy theorist for digging too hard into the mysterious death of a close colleague, a death that turns out to have been covered up by the officer who oversaw the case, Hwang Sun-cheol, who is himself later murdered by a man named Jeong Seok-gyo over an unrelated grudge, something Jeong casually reveals to Gu Rapa-illeo during questioning. A couple of Mun-jae's surviving old classmates visit him as well, closing out a story that, throughout its run, also drew some reader controversy: an early prologue scene showing Mun-jae aroused while watching his neighbor shower was criticized as gratuitous sexual objectification, and a later chapter was criticized for equating misandry and misogyny without addressing their different origins. The author apologized in an afterword, explaining the prologue scene was meant to set up the later reveal that Mun-jae, the watcher, was actually the one being watched all along, not meant as titillation.

Thematic Core

The title Field Mouse comes directly from the folk tale in which a mouse eats a human's fingernail clipping and takes on that person's face and identity. Every layer of the story reflects this:

• The doppelganger literally becomes Je Mun-jae.

• Oh Gi-wan was Je Mun-jae's "brother" before Mun-jae was born, then discarded. He spent his life haunting the edges of Mun-jae's existence.

• Mun-jae himself had stolen the identities of ghostwriters to become a "successful writer."

• Even Mun-jae's most personal childhood memory turns out to belong to someone else.

 wayzzzbon:

Can you please tell me where to read it in English? I tried to find it… 

I don't think it's available in english...

Another K-Drama with an unlikeable protagonist. Does Pinocchio learn how to become a real boy, or will he get turned into a donkey?

LucyL:

Based on what you've written, 20 Eps doesn't appear to give enough time to this to do it justice. Do you think it'll have a 2nd season, based of course on the reception of these 10 episodes?

It is actually listed as a limited series / miniseries, so it looks like it's meant to be a one-and-done. 😭 They'll have to fit the entire 95-chapter story into those 10 episodes somehow.