In Portland, Oregon, Peter Derns meets with his psychiatrist, Dr. Ron Feldman, and learns that his paranoia has improved, and that Feldman believes they should end their sessions. Peter returns to his job as a marketing manager for a food company named “Mrs. Appleby’s,” and makes a presentation to the board suggesting they launch an oatmeal cookie to their product line. President Charlene Towne is impressed, and asks Peter to submit a report the following day. Peter is surprised to learn that a New York company named Bart Foods has taken over their company, and worries that his promised promotion to vice president is now on hold. When his assistant, Lance, goes on paternity leave, Peter arrives to find that a beautiful temp named Kris Bolin has been sent to fill in as his assistant. He is impressed when Kris quickly takes over and helps him complete his important report due that afternoon, and he invites her to celebrate at a “secretaries day” lunch. When his colleague, Jack Hartsell panics at the sight of a wasp, Kris smashes the insect with her hand. Jack thanks her and explains his life-threatening allergy to wasp stings. Later, Peter asks Kris about the people in a photo on her desk, and she tells him they are her husband, Mark, and daughter, Lizzy. Kris organizes Peter’s computer files and asks for his expense account password to put his accounts in order. In time, Peter tells his friend, Brad Montroe, he is interested in having an affair with Kris. However, he dismisses the idea, believing it would be better if he worked on his strained relationship with his estranged wife, Sharon, and son, Nathan. Brad warns Peter that with the Bart Foods takeover, they will be rivals at competing food companies. Kris continues to prove herself a valuable assistant, and tirelessly helps Peter after hours with the oatmeal cookie campaign. When Kris accepts a lunch date with Jack Hartsell, Peter warns her of his intentions. However, Kris claims she is hoping Jack will offer her a permanent position as his assistant, knowing that Peter’s assistant, Lance, will soon return. Peter explains that Jack is competing against him for promotion to the vice presidency, and cautions that he will ask Kris for “dirt” on him. Kris accuses Peter of being paranoid. Soon after, Lance returns, and Peter wishes Kris good luck. While trying to fix a jam in the industrial paper shredder, Lance unplugs the machine before reaching inside. However, the machine springs to life and mangles his hand, and Kris is re-hired as Peter’s temp. In time, she tricks Peter into calling his psychiatrist, and listens in as he speaks to Dr. Feldman. She learns that he was seeking treatment for paranoia, and that he is ready to reunite with his wife. When Peter learns that Kris lied about her college education, he becomes suspicious of her motives. Later, he mentions to Kris that Jack is being favored for the promotion over him, and jokingly asks her to kill his competition. While driving to work, Peter passes Jack’s vehicle on the side of the street and sees him slumped over the steering wheel. Upon inspection, Peter discovers that Jack has died from a bee sting. Brad Montroe visits Peter at work, and spies at the top-secret cookie file on his desk. Kris becomes jealous when she sees that Peter has hung a picture of him and Sharon in his office. Over drinks, Peter tells Kris he ruined his marriage by constantly accusing his wife of having affairs, and admits he was seeing Dr. Feldman to address his paranoia. He confesses that his mother was unfaithful to his father, which damaged him. Kris admires his passionate nature, and tells him she fantasizes about being with another man. However, Peter insists that Kris’s husband is waiting for her at home. On the street, Peter is approached by his angry wife who insists they were supposed to have dinner. She asks about Kris, and accuses him of buying her jewelry for which Sharon received the bill. Peter confronts Kris the next day, and she makes excuses about buying herself a watch on his account, and promises to pay him back. However, Peter later fires Kris for her questionable actions, and is stunned when she tells him she was hired as a marketing manager at the firm. She credits Peter for her promotion, and gives him an antique letter opener as a thank-you. Peter again invites Sharon to dinner, much to Kris’s chagrin. Sometime later, Peter conducts a market research test at a supermarket, offering samples of their new oatmeal cookie to customers. Peter watches in horror as they bite into the cookies and their mouths fill with blood. Learning that their was glass inside the baked goods, the company suspects sabotage. When Peter tells his boss, Roger Jasser, that he suspects Kris of sabotaging the market test, Roger accuses Peter of being paranoid. At a company picnic, Peter witnesses Kris and Roger Jasser having a heated argument, and later, Peter is shocked to find that Roger has hanged himself. After the funeral, Peter learns that both he and Kris are in consideration for Roger’s position as vice president. Later, Peter tells Brad Montroe that Kris is playing games with him. In time, he investigates her former employer and learns that her previous boss has since died. When he tells Sharon of his distrust in Kris, she tells him he is paranoid and should return to Dr. Feldman. Peter is shocked when he sees Kris and Brad together at the gym. He invites Kris and her husband over for dinner, and accuses her of not actually having a family when she makes excuses for not being able to come. Kris makes a scene in the lobby and exclaims that her husband recently left her. In time, Peter is accused of leaking company information when confidential corporate information is found on his computer. Before being sent home, Peter publicly accuses Kris of killing Jack Hartsell and scheming against him. Peter gets drunk with Brad, and asks why he was at the gym with Kris. Brad explains that Kris was simply asking about job openings at his company, and accuses Peter of overreacting. The next day, president Charlene Towne apologizes to Peter after discovering that the research department accidentally sent him the incriminating information found on his computer. She credits Kris for pointing out the mistake, and offers him the position of vice president. Charlene sends Peter and Kris out of town to oversee production of the new cookies. Peter finally relaxes, and as he drives with Kris in her convertible, he apologizes to her. When the brakes give out along a winding cliff, Peter frantically drives onto the side of the road. Afterward, he discovers that Kris’s brakes have been tampered with. Later, Peter asks Kris why she lied about her background, and she explains that she had to do so to get ahead. Peter receives a message from Charlene saying that she is on her way to meet him at the cookie factory and receiving his message about an emergency there. Confused, Peter races to the factory and finds a murdered security guard, stabbed with Peter’s antique letter opener. He sees Kris lying on the ground, and telephones police, before being hit on the head from behind. As he recovers, he sees Charlene and Kris fighting. Peter knocks Charlene over the side of a walkway to rescue Kris from being strangled. Before falling to her death, Charlene warns Peter about “the pictures.” After he collapses from his head injury, Kris calls an ambulance. In time, Peter reconciles with Sharon, and she apologizes for accusing him of being paranoid. He returns to work and is promoted to president. Inside the boxes being removed from Charlene’s office, Peter sees several picture frames containing the same stock image of a man and child, and he recognizes the image as the one Kris claimed to be her family. When Kris enters, he shows her the insinuating frames, and accuses her of setting up Charlene. Kris makes endless excuses, but Peter ignores her. After telephoning police to have her arrested, he fires her.