) is a Bong Joon-ho film, starring Kim Hye-ja and Won Bin. Yoon Do-joon, a mentally-deficient young man, is thrown in prison for the murder of a local girl, Moon Ah-jung, after a night of heavy drinking. Mother believes that her son is innocent, and tries her damnedest to get Do-joon Yoon to remember details that will help his case. The help of others is enlisted, too, but not all are reliable — prompting Mother to take things into her own hands, even if danger seems to lie just around the corner.
Contains examples of:
- Amnesiacs Are Innocent: Played with. Do-joon follows a girl he doesn’t know after a night of drinking before the crime scene where she was murdered is shown, but her past is revealed to be very shady, making it fairly apparent he didn’t do it, but can’t remember what he did do that night because of his amnesia. The end of the film reveals he actually was the murderer—her shady background made her aggressive towards him and accidentally hit his Berserk Button.
- Ax-Crazy: Subverted. Ah-jung’s boyfriend is suspected to be one and accused of murdering her at the end of the film, but it turns out he’s actually very docile and it was Do-joon who killed her.
- Berserk Button: Don’t call Do-joon a retard, and don’t make fun of him in around Jin-tae, either.
- Black Humor: On occasion.
- Brain Bleach: Do-joon’s mother has needles that can erase painful memories.
- Bungled Suicide: The mother tried to do a murder-suicide to herself and Do-joon using insecticide. It failed, leaving Do-joon in a state of Trauma-Induced Amnesia.
- Cassandra Truth: At the end of the film, no-one believes Ah-jung’s boyfriend explanation as to how he got her blood on his shirt (they were having sex when she got a nosebleed), allowing Do-joon, the real killer, off the hook.
- Chekhov's Gun: The needles from Brain Bleach above. The mother tries to get him to use them when he remembers his mother trying to commit a murder-suicide on them, and finally uses them on herself to forget everything she’d gone through at the end of the film.
- Clear Their Name: Played with. It turns out Do-joon did kill Ah-jung after all; once his mother finds out, she kills the only witness. The police come to believe it was Ah-jung’s boyfriend instead. When the mother gets to talk to him and find out he has no family members who could clear his name for him, she starts crying.
- Dance Party Ending: Probably one of the most gut-wrenching examples out there. The mother is on a bus tour meant for showing gratitude for mothers; all the other mothers are dancing happily, while she sits in her place, horrified at what she’d gone through. She then uses the needles she can use to erase memories on herself and joins the party.
- Dead Guy on Display: Ah-jung is left on a rooftop for everyone to see. A detective says the person who murdered her did it to boast. He’s wrong; it was Do-joon who killed her, promptly forgot he did, and, in his state of panic, put her somewhere where she could be seen so that someone might help her, but it was too late.
- Downer Ending: Ah-jung’s boyfriend is wrongfully accused of murdering her while Do-joon, the real killer, and his mother, who covered up for him, escape justice.
- Even Evil Has Standards: Jin-tae, who freely blames Do-joon for vandalising an expensive car and leaving him with the debt, knowing he wouldn’t remember anything else, is extremely offended by the mother’s suspicion that he was the murderer and framed Do-joon, and he volunteers to help her find the real killer. This time, though, Do-joon actually did it.
- Foreshadowing: Do-joon recalls Jin-tae vandalising the rich people’s car when urged to recall what he was doing at the time of Ah-jung’s murder, indicating the unpredictability of his recalling technique. Later, he recalls his mother trying to commit murder-suicide with him.
- Forgetful Jones: Do-joon has severe amnesia, which he has to counter by rubbing his temples to trigger whatever he might have to remember. What might come up is usually helpful, but it’s anyone’s guess what it’ll turn out to be.
- Gory Discretion Shot
- He Knows Too Much: Do-joon’s mother kills the only witness who saw her son murdering the girl.
- Hide the Evidence: Do-joon retrieves his mother needles from the house where she murdered the only witness who saw him murder the girl.
- Karma Houdini: Do-joon, the real killer, and his mother, who kills the only witness, escape justice at the end of the film.
- Mama Bear
- MacGuffin: Ah-jung’s phone, containing pictures of the people she slept with.
- Man Child: Do-joon, whose amnesia leave him extremely dependant. He reacts violently when someone calls him an idiot. Reaches Psychopathic Manchild at the end, when it’s revealed he killed Ah-jung with a heavy rock because of this. The final scenes he appears in imply that he’s been cured to some extent of his amnesia, and thus no longer fits this trope.
- Maybe Magic, Maybe Mundane: The memory-erasing needles may or may not work. In the final scene, the mother still seems a little reluctant to join the party after erasing her own horrible memories, so either it takes time for it to work or it runs on placebo.
- Miscarriage of Justice: Ah-jung’s innocent boyfriend is accused of murdering her instead of Do-joon.
- No Name Given: The mother.
- Once More with Clarity: The scene featuring Do-joon drunkenly following a girl is revisited near the end of the film, proving that he was in fact the killer; the girl was Ah-jung, who called him stupid in a fit of resentment towards men, and he threw a heavy rock at her head in anger.
- Parental Incest: One of the suspects interrogated about the case voices his suspicion this about Do-joon and his mother, despite being told otherwise. He gets a tooth knocked out for it.
- Putting On My Thinking Cap: Do-joon rubs his temples intently to jog up his memory.
- Red Herring Twist: Played straight and played with:
- Near the beginning of the film, Jin-tae, accompanied by Do-joon, has a confrontation with a group of rich people, and he vandalises their car when they’re not looking; at the police station, Jin-tae blames Do-joon instead, knowing he won’t remember it otherwise, leaving him and his mother in a lot of debt, despite being aware of their financial difficulties. Shortly after, Ah-jung’s murder scene is shown, leaving the debt plot point mostly untouched.
- Friends of Ah-jung suspect she was killed for having compromising photos of her sexual partners. She wasn’t, but her sexual experiences did lead her to become resentful towards men, which caused her to lash out at Do-joon, who was her real murderer after all.
- Raised by Grandparents: Moon Ah-jung.
- Really Gets Around: Ah-jung again. She was notorious for sleeping around in exchange for sacks of rice to support her grandmother.
- Seamless Spontaneous Lie: Near the end of the film, the police think Ah-jung’s boyfriend is telling one when he says her bloodstains on his shirt came from when they were having sex and she had a nosebleed.
- Together in Death: Averted.
Mother: I should've used Gramoxon back then. If I had, we'd be frolicking in heaven's flower garden right now, instead of suffering.
- Too Dumb to Live: Do-joon is brought wearing a mask to Ah-jung’s murder scene to protect his identity; completely oblivious to what’s going on around him, he takes it off to wave hello at his mother. This is how the only witness who saw him murdering Ah-jung can confirm to himself that he knows who did it.
- Toxic Friend Influence: Do-joon’s mother is very displeased with him befriending Jin-tae.
- Trauma-Induced Amnesia: Do-joon’s amnesia stems from repressing the memory of his mother attempting a murder-suicide with him.
- Wham Line:
Do-joon: (To his mother) [I remember] you tried to murder me.