A married woman fights to save her marriage when her husband's sultry new co-worker takes extreme measures in order to steal the man she has an obsession for. 

After more than 20 years of marriage, Dana and Kurt find themselves drifting apart. Their daughter is in college and their pre-teen son yearns for independence. A gifted painter, Dana spends much of her free time on her paintings to keep her sanity.

Things grow more bothersome for Kurt when he meets the new office assistant. Heather is a bombshell on the outside and turns heads wherever she goes. The moment she sees Kurt, she knows this is the man for her. She goes out of her way to please him, despite the fact that she works for the entire office. Her mannerism troubles Kurt, who does his best to keep his distance.

Just when Dana finally gets a break after a new cafe wants to showcase her artwork, Kurt's office Christmas party begins a spiral for the Bartons into Hell. Heather makes sure Kurt drinks too much so she can take advantage. When he rejects her advances, Heather turns her anger on Mary, the sweet receptionist. Armed with incriminating information on Heather, she tells a co-worker that she will speak to Kurt about her in the morning. Morning never comes for Mary due to Heather poisoning her tea.

In order to cause a riff in Kurt's marriage, Heather steals his keys, makes copies, and enters their house when they are gone. She also plants her handkerchief in Kurt's suit jacket so Dana will surely find it. Kurt swears he has never touched Heather but the evidence begins to pile up against him, to the point that Dana makes him leave.

Kurt's continuous rejection of Heather sends her off the deep end. Her sister suspects she may have stopped taking her medicines for mental issues and reports her to the police. The same detective who handles the mysterious death of a Barton neighbor speaks with her. When Detective Williams investigates Heather's apartment, he discovers just how unhinged she really is and tries to contact Kurt.

But it's too late. Heather has taken Dana hostage while the kids are out of the house and assaults Kurt when he comes over. Jenny, the eldest Barton child, arrives home after a movie to find her parents tied up by Heather's hand.

Dana manages to slip out first, followed by Jenny. Feeling that she has lost, Heather decides it's time to kill the man who refuses to love her. Dana steps in to save her husband but finds she cannot do it alone. Thankfully, Detective Williams arrives in time to take Heather down before she can do more damage to the Barton family. The experience brings Dana and Kurt back together, as each has learned to cherish the other before something, or someone, takes it all away.