Little Children from Impersonable Studios on Vimeo.

Sarah Pierce (Kate Winslet) is a former campus feminist and academic who is now a reluctant homemaker and mother in an upper-middle class suburb of Boston. Feeling stifled and aimless in her role as a mother, Sarah views her young daughter Lucy as a nuisance (describing her as an "unknowable little person"), and it doesn't help that Lucy refuses to do almost anything Sarah asks, such as get into strollers or carseats. Sarah feels out of place around the tedious and judgemental Stepford-like mothers she encounters on a daily basis at the local playground. Her marriage has become loveless, and she catches her husband masturbating to online pornography with a pair of panties over his face. Her reaction is to buy an eye-catching red bathing suit from a department store catalog to get the attention of Brad. Brad Adamson (Patrick Wilson) is a former college football player who's married to Kathy (Jennifer Connelly), a documentary filmmaker. The couple have a young son, Aaron. Brad is depressed and frustrated, unable to deal with his non-dominant position in the relationship, as his wife is the breadwinner and he is a stay-at-home father who has failed the bar exam twice. Each day, he leaves home with the pretense of going to the library to study, but in actuality he watches skateboarders at the park. He joins a policeman's touch football team at the urging of a friend, Larry Hedges (Noah Emmerich), a disgraced former police officer. Early in the story, Sarah and Brad meet on the playground, where Sarah suggests they hug to shock the mothers nearby. Brad ups the ante and plants a kiss on her lips. While the other mothers freak out and take their children away from the playground, it's apparent that Brad and Sarah have discovered a sudden attraction. Weeks pass before Sarah musters the gumption to take Lucy to the pool, where she knows Brad and Aaron often go. Over the course of several regular visits, they get to know each other while their children also bond. After Brad, Sarah and the children are caught in a rainstorm at the pool, they rush to Sarah's house. The children are already asleep, and are put to bed upstairs for a nap. While Sarah dries their beach towels so that they can sit on the furniture in their soaked clothes, Brad mills about the house and comes upon a book of poetry in Sarah's study. He finds a picture of himself, shirtless and in the pool wedged in the book. Realizing that Sarah has feelings for him, he surprises her in the basement with another kiss. Brad and Sarah have a moment alone in the basement at Sarah's home, where they kiss and have sex in the laundry room. Meanwhile, Ronald "Ronnie" James McGorvey (Jackie Earle Haley), who has served a prison sentence for indecent exposure to a minor, has moved back into the neighborhood to live with his mother. Larry launches a hate campaign against Ronnie, handing out posters, vandalizing his house, harassing and almost assaulting the man and his mother. Ronnie's mother admonishes Larry, saying that Ronnie would never have done what Larry did. It is revealed that Larry accidentally shot a 13-year-old boy at a mall during his time as a policeman, and left the force after being diagnosed with post-traumatic stress disorder. He takes out this anger on Ronnie. Ronnie goes to the neighborhood pool and the police are called. Ronnie's mother (Phyllis Somerville) sets him up on a date, though he tells her that he doesn't desire women his own age. The date starts off well but ends with him masturbating in his date's car as he looks at a nearby playground. As his date cries helplessly, he threatens her to keep quiet. Sarah becomes increasingly serious in her affair with Brad, becoming tearful at not being a part of his life the way Kathy is. She stakes out and watches Brad and his family on weekends, the only time she and he can't be together. Kathy, after hearing Aaron speak about his new friend, Lucy, encourages Brad to invite the Pierces over for dinner. At dinner, Kathy picks up on the sexual tension between Sarah and Brad. Kathy enlists her mother to spy on Brad during the day and keep him away from Sarah. At a football game, Brad is surprised, then delighted to find Sarah alone in the bleachers cheering him on as he scores the winning touchdown. After making out on the field, Brad asks Sarah to run away with him. They agree to meet at the park the next night. A drunk Larry goes to McGorvey's house and further harasses him, using a megaphone to wake the entire neighborhood and warn them about Ronnie. When Mrs. McGorvey tries to stop him, Larry pushes her down. She has a heart attack, dying later in the hospital - but is able to write her son a final message in a note: "Please be a good boy." Ronnie is overwhelmed at losing the one person who loved him, and goes on a rampage throughout the house, crying hysterically. He only seems to achieve an eerie calm when he finds a kitchen knife in the drawer. Sarah packs a bag hastily, and takes Lucy to the playground to wait for Brad. Brad has said good-bye to his son and packed up some belongings. He sneaks past his unsuspecting wife and runs to the playground, but is again transfixed by the young skateboarders - who finally speak to him, and dare him to try just one jump on a short stair rail. Brad can't resist. Even though he "almost nailed it, dude", he falls and blacks out. Sarah leaves Lucy by herself on a swing while trying to comfort Ronnie, who has run into the playground, crying hysterically. Her daughter goes missing and Sarah runs into the street, screaming Lucy's name. She is frightened into realizing that leaving Richard would be a terrible mistake. Once she finds Lucy, transfixed by a street light and the bugs that it attracts, Sarah tearfully embraces her daughter and goes home. Brad is taken to the hospital and asks the police officer who was first on the scene - one of his football teammates - to call his wife. One of the skateboarders also discovers a note addressed to "Kathy" and gives it to Brad. The note was his goodbye to Kathy - a note that we'd been led to believe he'd left on the nightstand, and now only discover that he didn't have the courage to. Larry comes to the park to find Ronnie and apologize for harassing him. Noticing blood dripping off of the swing on which Ronnie's seated, he is horrified to discover that Ronnie has castrated himself with the kitchen knife so that he can "be a good boy" as his mother asked. Panicked, Larry picks Ronnie up and takes him to the hospital. They arrive just as a concerned and doting Kathy meets Brad's ambulance at the emergency room doors. The film ends with an image of a saddened Sarah sleeping alongside Lucy in their home with the film's narrator stating: "You couldn't change the past. But the future could be a different story. And it had to start somewhere."