Creator/EllenPage and Catherine Keener star in this dramatization of the real-life story of Sylvia Likens and Gertrude Baniszewski. Sylvia and her sister are left for an extended stay at the home of Gertrude and her six children. Times are tough and the increasingly unstable Baniszewski snaps and begins taking out her anger on Sylvia, repeatedly abusing and eventually torturing her. Things get worse when her kids and others from the neighborhood join in.
!!This film provides examples of:
* AdultFear: The worst fear of every parent who left their child in the care of a friend's family.
* AffectionateNickname: Sylvia's father calls her "Cookie."
* BasedOnATrueStory: Based on the murder of Sylvia Likens, a.k.a. "The Illinois Torture Murder." All dialogue from the courtroom scenes are drawn directly from the court transcripts.
* BlatantLies: Gertrude's story about Sylvia going to juvie.
* CompositeCharacter: Patty Ryan is a composite of three real-life girls involved in the historical events - Darlene [=MacGuire=], Anna Siscoe and Judy Duke.
* CreepyCircusMusic: The end credits, where [[CreepyChildrenSinging a children's choir]] imitates the piping of a circus calliope.
* DestroyTheAbusiveHome: The ultimate fate of the Baniszewski home. While plans were made to restore the house as a shelter for abused girls, funding fell through, with many in the community blaming lack of donations on the location being too heavily overshadowed by the murder. Two years after the film's release and almost forty-five years after Sylvia's murder, the house was demolished.
* DisproportionateRetribution: Much of what happens to Sylvia falls under this. The first beating happened because the girls' parents' payment was late, and because Gertrude believed Sylvia was telling lies about Paula.
* DyingDream: The scene of Sylvia's escape and reunion with her parents near the end.
* ForegoneConclusion: The fate of Sylvia.
* HopeSpot: Sylvia's DyingDream of escaping and reuniting with her parents. You know it won't last, but still.
** There's also a point where, after spending all of her time torturing Sylvia, Gertrude gently washes her and is able to interact with her calmly, indicating that she's got a grip again. She loses it as soon as the local church's priest speaks to her about suspicions that Paula is pregnant, causing her to start lashing out at Sylvia again.
* HowWeGotHere: The film opens with and switches back and forth to the court trial of Gertrude and the others.
* HistoricalVillainDowngrade: What Gertrude did to Sylvia in real life was even worse than what the movie shows. The same applies to Paula, whose portrayal in the film implies that she had some sympathy for Sylvia. The RealLife Paula felt the same about torturing Sylvia as her mother did.
* JustFollowingOrders: The excuse that many of the people involved with Sylvia's death give.
* KidsAreCruel: What Gertrude did was horrific enough, but that so many other kids would join in makes it even worse.
* MamaBear: Most of the abuse starts when Paula complains to Gertrude about Sylvia "spreading lies."
* MarkOfShame: Gertrude (and later Ricky, when Gertrude is unable to finish) burns "I'M A PROSTITUTE AND PROUD OF IT" on Sylvia's stomach with a hot needle.
* MayDecemberRomance : Gertrude and Andy. Keener was 48 at the time of filming, and Creator/JamesFranco was 29. A case of RealLifeWritesThePlot, as the real "Andy" was 18 to Gertrude's 34 when they began dating.
* [[spoiler: MyGodWhatHaveIDone: Maybe. By the end, when Gertrude is sentenced, her kids cry at the fact of their actions ''and'' the loss of their mother. When Gertrude is in prison and sees the spirit of Sylvia, she begins to tear up and tries to mouth the words "I'm sorry", before Sylvia fades away]].
* PosthumousNarration : Sylvia is telling her own story.
* TheSixties: A rather darker side thereof--less free love and more secrecy and lack of child protective services.
* SlutShaming: Gertrude does this to Sylvia for allegedly flirting with a boy.
* SocialServicesDoesNotExist: Very nearly literally. Many laws regarding mandatory reporting of suspected abuse came into being directly because of this case.
* TakeMeInstead: When Gertie is about to beat both Likens girls, Sylvia offers to take both beatings to spare her disabled sister.
* TeenPregnancy: Gertrude had her oldest daughter Paula at a young age, and Paula herself gets pregnant by her cheating boyfriend. Gertrude is unable to deal with the thought that Paula made the same mistake she did, leading her to blame poor Sylvia and ultimately torture her to death.
* TortureCellar: Where Sylvia is eventually kept.
* WhereAreTheyNowEpilogue: In the final scenes, Sylvia relates the fates of many of her tormentors.
* WoobieDestroyerOfWorlds: Gertrude is this initially as we see her fall apart from the stress but it becomes harder and harder to sympathize with her as her actions become more horrific.
* WouldHurtAChild: Gertrude Baniszewski.
* YankTheDogsChain: There comes a point where we're lead to believe that Sylvia will escape and be reunited with her family. The audience knows this won't last.