Taken from www.themoviespoiler.comThe movie opens with a African-American family moving into their new home. The family consists of Derek Charles (Idris Elba), his wife Sharon (Beyonce Knowles) and their baby, Kyle (Nathan and Nicholas Myers). The drive up to their new home and Sharon removes the sold sign and they go inside. While the baby sleeps, Derek and Sharon play a game of hide and seek in the empty rooms; this includes a tour of the attic, which is only beams and insulation. The game ends in their bedroom where the two enjoy a quickie while awaiting the moving van.When the movers arrive, Sharon directs the layout of the furniture and Derek heads into his office. Arriving at his office, he jumps into a crowded elevator and notices a white, blond hot chick (Ali Larter) carrying a stack of files. She remains in the elevator after everyone else gets off. She checks him out when hes not looking and he does the same. He asks if shes a client, she says shes a temp and this surprises him. When she drops all the files, he bends to help her and their hands touch. Derek looks uncomfortable and she smiles.When he gets off on his floor, she does the same. He asks her whom shes there to see and she says 'Derek Charles'. He tells her to watch out because he heard Derek Charles is a real asshole and tells her good luck.She later realizes his little joke and drops the files off with his assistant. Derek is a very successful asset manager with a large firm.As Derek leaves for the day he tells good luck on her next assignment and she says the company is actually keeping her for a few days, but he doesnt hear her, as he never stopped walking. She looks a little sad and turns back to her computer.The next day Derek arrives at work to find the temp, who introduces herself as Lisa Sheridan sitting at the desk of his assistant, Patrick (Matthew Humphreys). He asks what happened to Patrick and she replies, stomach flu. He says, "Well grab a pen and pad and lets get to work."Lisa sits across from Derek and he rattles of a list of to dos, many of which she has already taken care of. He asks if hes going to fast and she says, "No, I'm waiting for you to catch up".She proves to be very efficient and attracts the attention of most of the men in the office including Dereks best friend Ben (Jerry O'Connell) and his boss Joe Gage (Bruce McGill). Both of who comment on Dereks good luck. It seems, his wife was the last hot chick working in the office and Derek snatched her up and married her and now he has the new hot chick working for him.Over the course of the next few days, Lisa proves to be a creepy but very capable assistant. She even listens in on Derek and Sharon's conversations.When Derek and Sharon are talking one night, she asks why he didnt return her call and he says I didnt get the message. He then tells her the new girl got the message wrong and gave him the wrong name, (I think she said Cheryl). His wife asks him where is Patrick and he tells her out sick, she asks, I thought we agreed no female assistants? and tells him to get rid of her. She asks what does Lisa look like and he replies, "plain".Patrick returns and he breathes a sigh of relief that Lisa is gone, but then he sees her at the desk of Marge (Bonnie Perlman) who is Joe's assistant. It appears Marge also has the stomach flu. Derek looks like he feels just as sick when he sees her.At home he and Lisa are discussing her future and her desire to go back to school and finish her degree. He would rather Sharon stay home with Kyle, but she reminds him that he promised after the baby was born that she could go back to school.A few days later, Sharon brings Kyle to the office and is sitting in Derek's office talking when Lisa comes in for a report Joe is requesting. She comes over and introduces herself to Sharon who calls Lisa by the wrong name. She corrects Sharon and begins to coo and fawn over Kyle before heading back to work. Sharon says theres one thing that girl aint and its plain. Derek says he wouldn't know because the only woman he notices is Sharon. She rolls her eyes and they take Kyle around the office. Lisa goes into Derek's office, looks at a photo of his family and opens his CD case and looks at the music inside and notices one labeled Credo.The next day theres a CD on his desk and he inserts it to find its a live recording of the band. Lisa sends him an IM saying she knew he liked the group and its a bootleg copy. He tells her the band rocks and get back to work. She smiles as she watches him bop to the beat.The next day at work, Derek walks into the break room and finds Lisa in tears. He says "hi" and makes his way to the refrigerator for his lunch. As he turns to walk out and almost makes it out of the door before turning and asking if shes okay. She tells him she was just dumped and wonders if theres something wrong with her. He tells her that she is a smart and beautiful woman and if he was single He cuts himself off and pats her arm and says everything is going to be okay. As hes leaving Ben walks in and looks at the two of them questioningly.Patrick and Lisa have bonded and he asks her how often did she listen in on Derek's conversations. She laughs and says we need to have cocktails and clue her in on all the office gossip.The office Christmas party approaches and no spouses are allowed. Sharon reminds Derek to remember to eat something before drinking and have fun.At the party Derek dances with Marge for a little while before Lisa cuts in. She maneuvers them to the mistletoe and tells Derek that if he doesnt kiss her the staff will talk more than if he did kiss her. He says well Ill have to take that chance, laughs and walks away heading to the mens room. When he walks into the stall, Lisa suddenly appears and follows him inside. She is all over him, trying to kiss him, pulling his shirt out of his pants as he tries in vain to avoid her. They hear a drunken guy at the urinal whos trying to peek into the stall to see whos inside making out. He keeps shushing Lisa and she keeps trying to get into his pants. When the guy leaves he forcefully pushes her away as she asks, "What's wrong?" He tells her to stop and leaves the mens room. He grabs his jacket and hurriedly leaves the party. As Lisa returns to the party smoothing down her dress, Patrick who saw Derek leave first, makes a catty remark and Lisa says, "Oh, dance with me you queen." They both laugh as they dance.That night as he slips into bed Sharon asks how was the party and he says the same old same old. She asks, Did anything exciting happen? He says nope and pulls her close as she goes back to sleep.The next day Derek sees Lisa at the office and she acts like nothing happens. He gives her a wide berth the entire day. Later that day she comes into his office and apologizes for her behavior. Derek tells her dont worry about it. She smiles and leaves. Derek later confides to Ben about what happened at the party. Ben jokes that he is so jealous and Derek tells him its not funny. He tells Ben that hes going to HR to get rid of Lisa and Ben tells him to be careful; she may turn it around on him. He goes to see the HR Manager Hank (Rick Ruccolo) and says he needs to talk to him about Lisa. Hank tells him Lisa has resigned. Derek breathes a sigh of relief and tells Hank that he thought she might have been in over her head.That evening in the parking garage, Derek gets into his car to leave. As he turns to fasten his seatbelt, Lisa jumps into the car wearing a trench coat. He asks her what the hell is she doing and she opens the coat to reveal a sexy bra/panty outfit complete with fish net stockings. She tells him, its okay now that they no longer work together. He tells her to get out of his car. She continues to squirm in the seat and he yells louder to get out of his car. She asks, "Why are you being this way?" He reaches over her, opens the door and starts to push her out. She screams, "you are an asshole!" and gets out of the car enraged. He peels away with her standing there.That night, he vows to tell Sharon whats going on. He walks into the house and Sharon is sitting at the dining room table holding the phone and a glass of wine. He sees the sad look on her face and asks whats wrong. She says "I just spent the last hour and a half talking my sister off the ledge". It seems her husband had confessed to having an affair and is leaving her. Well of course, he doesnt tell her about Lisa. Big Mistake.After a New Years Eve party, Derek and Sharon return home when his email beeps. Derek sees its from Lisa and tries to ignore it. Sharon says it may be word on the big account Derek has been working on and he should open it. When she goes into the bathroom, he opens the email and its a sexy picture of Lisa, which multiplies into countless windows that cover his screen. As he frantically tries to close them all, he tells Sharon its just spam.At work the next day he e-mails Lisa, saying simply, "leave me alone". The message goes right past her as she responds with a big happy face that winks at Derek.A few days later, Derek is packing for a work retreat. Its being held at a local hotel and the guys at the office are all looking forward to it. She tells him to behave and dont get too drunk doing all that male bonding.At the retreat, Derek, Joe and Ben and another co-worker are sitting around the pool drinking when they decide to visit a mens club for some adult entertainment. The waitress brings Derek a drink and says its from the woman at the bar. As he turns he can only see a partial view of the woman. Dereks phone rings and he answers telling the guys its Sharon. As he walks away to talk to her, he sees Lisa approaching him. He quickly hangs up, leaving Sharon puzzled. He asks, "What the hell are you doing here?" She tells him well of course, Im here to see you. He tells her shes crazy and needs help. She tells him how much fun they can have, and he looks at her as if shes sprouted another head. She tells him to come up to her room and tells him "I'm in 610". He informs her that he is not coming to her room. She says sweetly, "or should I come to yours?" He tells her flat out that nothing is going to happen between them and to get some help. His phone rings and when he turns to answer Lisa slips a powdered substance in the glass. He turns to leave and comes back and grabs the glass saying goodbye for good Lisa. He heads back to the table and says hes in for the club with the rest of the guys.Later that night, Ben and Derek are walking down the hall. Derek is visibly drunk, swaying into the walls and everything. He tells Ben the last drink did him in. He goes into his room as Ben reminds him of their 9:00 meeting. Derek falls across the bed moaning. He turns over to see Lisa hovering over him. Hes incapable of fighting her off as she rubs and massages and kisses him. Derek passes out with Lisa astride him.The next morning he wakes up in obvious hang over hell. He looks at the clock and realizes its already 9:30. He jumps out of bed and makes it to the meeting by 10:15. His boss Joe tells him hes glad he could make it as Derek slinks into his seat muttering about oversleeping. Two hours later, the meeting is still dragging on when the desk clerk interrupts to tell Derek his wife is in the lobby. Derek excuses himself and the man says shes right over there. Of course its Lisa. Now, NOW hes getting angry. She says, "I know youre bored in there so I thought Id rescue you, Wanna go have lunch?"Derek tells Lisa she really is insane. She starts rambling again about how he wants her, how he told her if he was single theyd be together and on and on. She then threatens to go into the meeting and tell them everything. He grabs her arm and yanks her toward the meeting telling her to do it, tell them the truth I want you to. Of course she hesitates and again asks, "Why are you being this way? " He says I dont want you! She then heads toward the room asking, "Who do you think they would believe?" He tells her in no uncertain terms that there will NEVER be anything between them and she needs to leave him alone. He turns and goes back into the meeting.Later on, Derek enters his room and lo and behold, Lisa is in his bed. He says, "Aw, hell no" and tries to yank her out of the bed. He then notices an empty pill bottle and the fact that shes unconscious. He calls 911. We later see Lisa on a gurney and Derek telling Ben hell explain it all later.That night, the phone awakens Ben. It's Sharon asking where Derek is, as hes not answering his cell and she hasnt heard from him. He tells her that maybe she should talk to Derek at the hospital. Of course she freaks out and heads over to the hospital. As she skids around the corner she sees Derek and runs to hug him. Before he can tell her what has happened, the doctor approaches him and tells him that it was a close call but Lisa will be all right. Sharon says, "Lisa, what the hell is going on?" Derek tries to calm her down when Detective Reese (Christine Lahti) walks up and asks to talk to Derek. The detective is asking questions and Sharon is asking questions and Derek looks constipated. When the detective asks why Lisa tried to overdose in Dereks bed, Sharon comes unglued. Derek is trying to calm her down and the detective keeps asking one loaded question after another. Derek tries to tell her that Lisa is crazy, but this falls on deaf ears. Lisa even gave Derek as her emergency contact. Sharon has heard enough and walks away with Derek following her. The ride home is tense and Sharon explodes as soon as the sitter leaves. She accuses Derek of sleeping with Lisa, which he of course denies. He tells Sharon about all the things that Lisa did and she asks "why in the hell am I just hearing all this?" She reminds him about their vow to always tell each other the truth. He says hes so sorry and orders him out of their house. Plates are thrown and tears are shed before he finally leaves.The next day at work Joe advises Derek that what happened at the retreat could open them up to a huge lawsuit and he takes Derek off the big account.Detective Reese visits Lisa in the hospital and questions her about their relationship. Lisa tells her that Derek is going to divorce Sharon and they will be together. She asks if Derek is there to see her. Detective Reese tells her that she doesn't think Derek wants to see her; as a matter of fact she knows he doesn't. Lisa asks, "well why did he send those flowers?" There is a huge bouquet on the table with a card reading, "I'm so sorry about yesterday, I love you. Derek."Detective Reese looks at the card and Lisa very skeptically. After talking with Lisa, Detective Reese meets with Derek and tells him about the flowers. He tells her he never sent Lisa flowers. Derek says that Lisa must have taken the credit card info when she worked in his office and sent the flowers to herself to make it appear to everybody that he cares for Lisa. Detective Reese also reveals a journal Lisa kept detailing all the intimate details of their romance, which of course never happened. Derek again stresses that Lisa is crazy and he's worried about what she might do. Detective Reese reassures him that he doesn't have to worry as Lisa is now in San Francisco with her sister.The next few scenes are of Derek in his hotel room, playing with his son and Sharon alone at home. We later find out that he has been out of the house for a few months. One day he drops his son off at home and tells Sharon that his birthday is approaching and asks if he can spend it with her. She agrees to go to dinner with him. She tells him she has a gift but will give it to him once she sees how the evening goes. During dinner he begs Sharon to let him return home. He tells her she and Kyle are his world and he wants his family back. She slides the box over to him and its his house key.Back at the house, the babysitter Samantha (Scout Taylor-Compton) is texting and listening to music as the doorbell rings. She opens the door and it's Lisa. She waltzes in saying she's a friend of Sharon's and she has a present for Kyle and heads upstairs. Samantha tries to stop her when Lisa says, "You mean Sharon didn't tell you I was coming?" She pulls out her cell phone and has a pretend conversation with Sharon. When she finishes, Lisa offers the phone to Samantha and asks if she needs to speak to Sharon, of course she doesn't or the movie would end here. She turns and says it will only be a second. Lisa heads to the nursery and stands looking down at Kyle. The next scene shows Lisa rocking Kyle and kissing his head. Lisa then leaves without Samantha even noticing.Derek and Sharon arrive home and ask Samantha how did things go. She says "fine and your friend stopped by". Sharon respons by saying "Friend? What friend?" They both bolt up the stairs and find the nursery empty. Sharon screams call 911 as they frantically search for Kyle. Derek runs for the car to search for him and sees Kyle in his car seat with a huge lipstick kiss on his forehead.Cut to the hospital and the doctor telling Sharon and Derek that the baby is fine. Detective Reese offers Derek and Sharon police protection and Derek asks if he should by a gun. Instead he opts for installing a security system.At the office, Patrick gets a surprise call from Lisa who he hasnt heard from in months. He tells her he could get fired for talking to her. She tells him dont worry you wont get fired and asks him hasnt he heard the news. He asks what news? She tells him Derek is divorcing Sharon to be with her. He laughs and says that cant be true because they are planning a big weekend visiting Sharons parents. Motor-mouth spills the beans that Kyle is with Sharons sister, Sharon is driving to her parents and Derek will travel by plane the following day. Lisa abruptly hangs up.Back at the house Sharon is preparing to leave for the weekend. She gets into her car and calls Derek to tell him she is heading out. He asks did she turn on the security system, she remembers that she didnt and heads back to the house. Cut to the house and Lisa breaking in through the back door and entering the house carrying a bottle of champagne and two glasses. She goes into their bedroom and takes off her clothes. Wearing Lisa's nightshirt, she sprinkles rose petals all over the bed.Downstairs, Sharon enters the house and is entering the alarm code when she hears the pop of the champagne bottle up stairs. She slowly climbs the stairs to investigate the noise. When she enters the bedroom Lisa is in their bed. Sharon says, "Oh, you really are crazy."Lisa tells her that she's sorry that their family is breaking up but she and Derek are in love and are going to be together. Sharon tells her to get out of their house. When Lisa approaches her, Sharon grabs her and slings her toward the door. At this moment the phone rings. Both women make a mad dash for the phone and Sharon grabs it first. It's Derek making sure she is okay. She tells him that she found Lisa in their house and then simply says, "I'm going to have to call you back," and then hangs up.Sharon turns towards Lisa, and a climatic and very brutal cat-fight begins. The two women kick, slap, punch, head butt and finally tumble their way down a staircase. While Sharon is stunned, Lisa gets up and runs back upstairs. Sharon is right on her heels and the women end up in the attic. Arming herself with a 2-by-4 piece of wood, Lisa proceeds to use Sharon's legs as batting practice. Balancing herself on some badass four-inch heels, Sharon backs up along a strip of wood, taunting Lisa to come and get her. Lisa swings and falls onto a weak portion of flooring and falls through. Hanging on for dear life, Lisa dangles from the ceiling and we get a view of the floor below and the huge glass coffee table below. Suddenly having a change of heart over letting Lisa fall to her death, Sharon suddenly grabs Lisa's hand and tries to pull her up. And in return the psychotic Lisa tries to pull Sharon with her. Sharon finally finds her cajones and pries Lisa's fingers apart and Lisa drops, crashing into the table below. Lying amidst the glass and twisted metal, Lisa slowly opens her eyes and tries to move. But the swinging chandelier gets her attention, weakened by her fall through the ceiling; it is hanging on by a cord. When it stops swinging, it suddenly falls spearing Lisa beneath it, killing her at last.Sharon slowly walks out the front door as Detective Reese drives up asking what happened. Sharon says, "You know what happened", and she walks into Derek's arms.