Following his discovery of the body of his wife (Amy Irving) in a bathtub after her apparent suicide, Dr. David Callaway (Robert De Niro), a psychologist working in New York City, decides to move with his 9-year-old daughter Emily (Dakota Fanning) to Upstate New York. There, Emily makes an apparently imaginary friend she calls "Charlie". Her friendship with Charlie begins to disturb David when he discovers their cat dead in the bathtub, whom Emily claims was a victim of "Charlie". Meanwhile, David suffers from nightmares of the New Year's Eve party that occurred the night before his wife died.
When a family friend, Dr. Katherine Carson (Famke Janssen), comes to visit David and Emily, Emily reveals that she and Charlie have a mutual desire to upset her father. Soon, they meet Laura (Melissa Leo) and Stephen (Robert John Burke) who are their neighbors. David is wary of their unusual interest in Emily. He later discovers that the reason for this is that the couple had a daughter who recently died from cancer and looked like Emily. Later, when David visits Laura, she nervously and ambiguously implies that her husband has begun abusing her in response to their child's death, emotionally and perhaps even physically.
David meets Elizabeth Young (Elisabeth Shue), a local woman, and her niece, Amy, who is roughly the same age as Emily. Hoping to cultivate a new, healthy friendship for Emily, David sets up a play date for her. Amy is anxious to become friends immediately, but the play date is spoiled when Emily cuts up Amy's doll's face. After Amy runs out of the house, Emily tells David that she doesn't need any more friends.
Despite the unsuccessful play date, David and Elizabeth hit it off. David invites her over to dinner one night, where Emily acts increasingly hostile towards her. Some time later, Elizabeth visits the house, hoping to make peace with Emily. When Emily tells her that she is playing hide-and-seek with Charlie, Elizabeth indulges her by pretending to look for Charlie. When she opens the closet, someone bursts out and pushes Elizabeth out a second-story window to her death.
After the police discover her car crashed near David's house, David asks Emily what happened. Emily claims Charlie caused her death by pushing her out the window and forced Emily to help him move the body. She tells David the location of her body. A terrified David discovers Elizabeth's body in the bathroom in a bathtub full of blood. David asks Emily where Charlie is, and Emily tells him that Charlie has "just left".
David, armed with a knife, goes outside, where he meets the neighbor who has become friends with Emily. David assumes that his neighbor is Charlie and begins to act aggressively. Becoming suspicious that David has killed his own daughter, the neighbor asks to see Emily, but David cuts the neighbor with his knife. The neighbor then calls the police.
Back in the house, David finds that, although he has been in his study many times (listening to his stereo and writing a journal), the boxes were actually never unpacked after the move. With this, David realizes that he has split personality and that Charlie is not imaginary at all, but that in fact "Charlie" is David himself. Whenever "Charlie" would emerge, David was in his study. Charlie was actually in control. David also realizes that under his Charlie personality, he killed his wife and then made it appear to be a suicide. He also fully recalls the events of the New Year's Eve party the night before his wife's death. Immediately after the countdown to midnight, David noticed his wife slip away. He followed her and caught her in a stairwell making out with another guest. "Charlie" was created as a way for David's rage to murder his wife, something that the docile David himself was too decent to do. Emily knew the entire time about her father's split personality, but did not tell him because she was unsure which personality murdered her mother, suspecting David until "Charlie" killed Elizabeth.
Once Charlie's identity and horrible deeds are realized to David, he becomes completely consumed by Charlie, leading him to murder the local sheriff (Dylan Baker), who arrives to investigate the previous altercation. Emily calls Katherine for help.
Katherine arrives and is pushed down the basement stairs by 'Charlie'. Charlie/David, determined to play a hideous game of hide-and-seek with Emily once again, starts counting. Emily dashes and hides. She tricks Charlie and manages to lock herself in her room. As Charlie tries to break in, she climbs out from the window and runs into the cave where she originally met Charlie.
Meanwhile, Katherine takes the gun from the dead sheriff, breaks out of the basement, and finds Charlie looking for Emily in the cave. Charlie pretends to be David and attacks Katherine when she lowers her guard. Katherine begs for David to come out and fight his murderous other personality. Charlie tells Katherine that David no longer exists; from the minute David discovered the truth about himself, this enabled Charlie to fully take over. Emily emerges from her hiding place, begging Charlie to let Katherine go. Her distraction allows Katherine to shoot Charlie, killing him at last.
Sometime later, in one of several endings, Emily is preparing for school in her new life with Katherine. But Emily's drawing of herself with two heads, suggests that she might also suffer from dissociative identity disorder.
This film has a total of five different endings, The US theatrical version had the following ending:
Preparing for school while living a new life with Katherine, Emily draws a picture of herself and Katherine, suggesting that everything is fine. But when the camera cuts back to Emily's drawing, Emily has two heads suggesting she now suffers from split personality. This ending is included as an alternate ending on DVD outside the US. Another four were included on the DVD:
Happy Drawing: The same as the ending in the US theatrical version, except that the drawing Emily makes of herself has only one head, suggesting that she is fine and does not suffer from split personality.
One Final Game: Emily is shown seemingly in a new apartment bedroom, and Katherine's actions mirror that of her mother's at the beginning of the film. She reassures her love to Emily and begins to leave the room. Emily asks Katherine to leave the door open, but Katherine insists she cannot. As the door shuts, a protected window is visible on the door. The next cut is of Katherine locking the door from the outside, revealing this assumed apartment bedroom is actually a hospital room in a children's psychiatric ward. Emily gets out of bed and does a Hide and Seek countdown. She nears the closet, opens, and smiles at her own reflection in the mirror.
Emily's Fate (International theatrical ending): Same as above in the psychiatric ward, but without the Hide and Seek countdown. This ending was featured in the international theatrical version.
Life with Katherine: An ending similar to that in the psychiatric ward, but in this ending Emily is not in a ward but her new home. After Katherine shuts the door, Emily gets out of bed to play Hide and Seek with her own reflection.
On the DVD, the main menu enables you to watch the film with any one of the five endings.Robert De Niro as David Callaway/Charlie
Dakota Fanning as Emily Callaway
Famke Janssen as Katherine Carson
Elisabeth Shue as Elizabeth Young
Amy Irving as Allison Callaway
Dylan Baker as Sheriff Hafferty
Melissa Leo as Laura
Robert John Burke as Steven
20th Century Fox released two versions of the film: the international version and the domestic version. Both versions received different endings. The domestic version was released in the US, while the international version was released to other countries. Both the international and domestic versions submitted to the BBFC were actually released to UK cinemas. Both versions passed for a 15 certificate for "moderate horror and violence". The film was released on DVD on July 5, 2005, in the US and on July 25, 2005, in the UK.
In its opening weekend in US theatres, the film grossed $21,959,233. In the US, the film grossed $51,100,486. The film brought in $71,544,334 internationally. Overall, the film grossed $122,650,962 worldwide.
It holds a 13% approval rating on Rotten Tomatoes based on 155 professional reviews. The consensus reads: "Robert De Niro and especially Dakota Fanning have earned some praise for their work in Hide and Seek, but critics have called the rest of the film derivative, illogical and somewhat silly." The film scored 35 out of 100 on Metacritic, indicating "generally unfavorable reviews". BBC Movies gave the film two stars out of five, commenting that "Robert De Niro continues his long slide into mediocrity with yet another charmless psycho-thriller." Roger Ebert of the Chicago Sun-Times gave the film two stars out of four: "There was a point in the movie when suddenly everything clicked, and the Law of Economy of Characters began to apply. That is the law that says no actor is in a movie unless his character is necessary." The New York Times said the film was hampered by budgetary restrictions and the Toronto Sun said it was one of De Niro's worst.