[[quoteright:310:https://static.tvtropes.org/pmwiki/pub/images/obsessed_2009.jpg]]
[[caption-width-right:310:Black and white text... Go figure.]]

A 2009 PsychologicalThriller film directed by Steve Shill and starring Music/{{Beyonce}} in her first serious role that doesn't relate to music.

Successful businessman Derek Charles (Creator/IdrisElba) is doing very well for himself. He's got a beautiful wife named Sharon (Beyoncé), an adorable son, and he and his family have just moved into their first house together. But after meeting an office temp named Lisa (Creator/AliLarter) on the way to his office, it soon becomes clear that his wife is not the only woman with feelings for him, and the harmless flirting of a crush quickly becomes quite a bit more serious than anyone expected.

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!!This film contains examples of:

* AbortedArc: There are quite a few plot points that are mentioned that really don't serve any purpose in the long run, such as Sharon's and Derek's history together in the old days at the company, or a discussion of a mutual friend cheating on his wife (which is why Derek decides not to tell her about Lisa) never being brought up again. This was played especially straight with the interracial aspect, in which there were plans for, but was apparently written out because the writer had just penned ''Film/LakeviewTerrace'' very recently.
* AccentUponTheWrongSyllable: Idris Elba throughout the film.
* ActionMom: Sharon proves to Lisa ''very effectively'' why she shouldn't have messed with her family.
* AllMenArePerverts: With a few camera shots representing Derek's POV and a few questionable decisions, the audience is lead to believe this.
* AboveTheInfluence: Derek Charles, amazingly even when "under the influence"
* AttemptedRape: Lisa attempts this twice. First, she tries to seduce Derek while drunk at the Christmas party but failed. The second time, she drugs him and drags him into her hotel room while he's unconscious. Whether or not she succeeds is left up in the air.
* AxCrazy: Lisa is manipulative, delusional and violent to the point where she attempts to take her rival down with her in the climax.
* ArentYouGoingToRavishMe: Lisa tries to taunt Derek into being aggressive with her on multiple occasions.
-->'''Lisa:''' Do it. Hit me. You can do anything you want to me.
* BenevolentBoss: Derek, as well as his own boss Joe, with whom he has a close friendship.
* BettyAndVeronica: Derek is the Archie torn between his lovely wife, the Betty Sharon, and the exotic Veronica, Lisa.
%%* CatFight: The inevitable showdown between Sharon and Lisa.
%%* CoolOldGuy: Joe Gage, Derek and Ben's superior.
%%* ChekhovsGun: The structural integrity of the boards in the attic.
* DoubleStandardAbuseFemaleOnMale: A large source of Lisa's manipulative power in the film, along with people around him questioning if he [[AllMenArePerverts might have lead her on]].
%%* DoubleStandardRapeFemaleOnMale: Well, more like attempted rape, for [[AllMenArePerverts the same reasons above]].
* DrivenToSuicide: [[spoiler: After being rejected by Derek one too many times, Lisa attempts to kill herself in Derek's hotel room by overdosing on a whole bottle of pills. Though, one might question if this was a genuine desire to die, or a desperate attempt for attention]].
* FauxFinalLine: Lisa tricks the babysitter into letting her into the house so she can kidnap the child. She pretends to have a conversation with Sharon (the child's mother) and even implies that she is angry. Then Lisa offers the phone to the babysitter, who declines it.
* FlatCharacter: Derek’s best friend and colleague Ben, whose only role in the movie is to make jokes about Lisa's attraction to Derek and to continuously goad him into straying. [[spoiler:Though he comes to regret this later.]]
%%* FreezeFrameEnding: The final shot of the film.
* HappilyMarried: Derek and Sharon, despite the few bumps in the road. Derek even says that he's this with Sharon.
* {{Housewife}}: Sharon is a stay at home mother, although she has plans of going back to school.[[spoiler: She later believes her plans of going back to school are the reasons for his alleged affair]].
* IgnoreTheFanservice: Rather than give into Lisa's advances, including one where she opens up her coat to reveal lingerie underneath it, Derek pulls her coat shut and demands that she get out of his car.
* JerkassHasAPoint: Ben, of all people, warns Derek against reporting Lisa to Human Resources out of fear that it could quickly backfire [[spoiler:given Derek’s own history of hitting on female workers.]]
* LadyInRed: Lisa, who wears a red dress when she arrives uninvited to Derek's party to seduce him. Also, see the cover.
* LikeGoesWithLike: There's Lisa, an office temp, who falls in love with her boss, Derek Charles (a black man) and attempts to seduce him and break up him and his wife Sharon (also black), by claiming that she had an affair with him.
* LoveMakesYouCrazy: Rather than playing mind games for sport, Lisa's motive comes across as really wanting to be with Derek, and also attributes his rejection of her to circumstances rather than how he feels.
** However, it's possibly subverted, as it's implied by her more morally questionable actions and some of her dialogue (especially in the last half hour where she ends up resorting to deceitful and manipulative tactics) that she's somewhat conscious of Derek's desire to not be with her.
%%* MamaBear: Sharon Charles when you try to break up her family and especially if you ''touch'' her son.
* ManipulativeBitch: Lisa. She constantly orchestrates events in the movie to further her quest to be with Derek, whether he likes it or not.
* MoodWhiplash: When Derek [[spoiler: finds Lisa unconscious in his bed, he is at first incredibly angry but then realizes she's not breathing so he starts CPR, but the whiplash comes from what he says while he's doing it, which is: "Breathe, bitch!" It's hard not to giggle when you can tell he'd like nothing more than to let her die, but is forced to save her to keep from being accused for murder.]]
* MsFanservice: Ali Larter, so no surprise. This time she tries to seduce Derek in lingerie under her coat.
* NotQuiteDead: Played with to the point of almost being [[{{Narm}} humorous]]. [[spoiler: Lisa first catches herself before falling through the ceiling, then catches herself while falling past the chandelier. She then falls through the glass coffee table, appearing to have fatally hit her head on one of its legs, but then opens her eyes. ''Finally,'' the chandelier falls from the ceiling and onto poor Lisa, ending her reign of terror on the Charles family.]]
* OohMeAccentsSlipping: Derek's "American" accent occasionally becomes muffled and ambiguous.
%%* PayEvilUntoEvil
* PetHomosexual: Patrick the assistant.
-->'''Patrick''': Watch out, girl. He's married.\\
'''Ali:''' All the good ones are married.\\
'''Patrick:''' Yeah, or straight.
* RelationshipSabotage: The movie's premise revolves around this trope.
* SassyBlackWoman: Downplayed, in terms of Sharon. She's mostly reserved and mild-mannered until the Lisa situation is brought to her attention.
* SeductionProofMarriage: Derek, who is happily married to Sharon, rejects Lisa's advances on him every time she attempts to seduce him out of his devote faithfulness and love for his wife.
* SexyCoatFlashing: Lisa tries this on Derek. It doesn't work.
* SlippingAMickey: When Lisa shows up at a business retreat, she drugs Derek's drink when he isn't looking.
%%* StalkerWithACrush: Lisa Sheridan.
* TakeMyHand: Sharon does this to Lisa after she was hanging on to what remained of the attic floor/ceiling. She accepts, but [[TakingYouWithMe isn't quite done fighting]].
* TakingYouWithMe: Perhaps just good ol' crazy, or maybe a bit of overlap with [[IfICantHaveYou If I Can't Have Him]].
* TooDumbToLive: Gee, go outside and wait for the police, or investigate the noise upstairs that is likely the crazy bitch in my house... Also, pretty much everything about the finale.
* VagueAge: The Charles' son. The boy is clearly a toddler, Sharon mentioned at the beginning that he was two, yet he doesn't speak a word throughout the film (not even baby talk) although they do mention briefly that he could say a few words, and Sharon later mentioned that he was conceived after Derek came home after ''last year's Christmas party'' drunk.
* VerbedTitle: Lisa's violent obsession with Derek that's the focus of the movie.
%%* ViolentlyProtectiveGirlfriend: Sharon Charles when you try to take her man.
* WhatHappenedToTheMouse: Ben is prominently featured in the first and most of the second act. He is last seen when [[spoiler:Sharon calls him about Derek’s whereabouts and he reluctantly hints at an affair with Lisa.]] Aside from one brief name-drop, he isn’t seen again for the rest of the film.
* WhatTheHellHero: Sharon, convinced that Derek had an affair, chews him out for hiding the truth about Lisa, [[spoiler:and subsequently kicks him out for three months.]]
* {{Yandere}}: Lisa for Derek. She starts off having an innocent crush on Derek as she starts her new job in his office. As the movie progresses, she becomes an obsessive and manipulative stalker who believes she and Derek are together. She attempts suicide after he spurns her feelings, and she does everything she can to split him and his wife up.
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