It centers around a woman named Melinda Gayle (Taraji P. Henson) who learns that not only has her husband Robert (Lyriq Bent) been cheating on her, but he has been leading a double life seeing another woman on the side — and has no further interest in continuing his relationship with Melinda.
As you might have surmised from the poster, she doesn't take it well at all.
- All of the Other Reindeer: Robert is hated by 90% of the cast, and it's justified most of the time.
- Ambiguous Situation: Melinda's retelling of the entire backstory. It is implied that she is leaving out a lot in her story such as how one family argument led to her and Robert sleeping in different rooms and showing no affection towards each other for weeks. The greatest hint towards this is when she tells Robert she wants a divorce. When he tries to argue against it, she threatens him with "you know I can be the motherfucking devil" and he quietly and immediately leaves after despite the fact that she does not talk about any incidents since the time she caught him cheating. While the film does not give the audience much reason to believe she's lying about any of the events and things said, it's very clear that she doesn't see anything she's done that may have contributed to the divorce and Robert moving on with Diana.
- Big Bad Slippage: Melinda slowly but surely becomes the film's Big Bad.
- Contrived Coincidence: Diana just so happened to inherit a position to give Robert an in to a company he can sell his battery design. When he had a coffee meeting with her, she accidentally left her wallet behind, which looks suspicious to Melinda and her family, especially after he ruined their delivery to an important client.
- Death by Irony: For all of the "dead weight" that Melinda is throughout the film, she eventually drowns via a dead weight in the form of the yacht's anchor.
- The Determinator: Robert refuses to give up on his battery invention and tries for nearly two decades to get it noticed. He finally succeeds, but at the cost of his marriage and dealing with his unhinged ex-wife.
- Foregone Conclusion: The film's trailers make it clear that Melinda is going to undergo Sanity Slippage.
- Foreshadowing: Melinda admits early during her narration that there is another side to her filled with uncontrollable rage that is the opposite to her usually cheerful self. After listening to Melinda's side of the story, the psychiatrist suggests that she could be suffering from a mental disorder, and that Robert is not the monster she makes him out to be. She gets upset and leaves. Then she plots to kill Robert and his new fiancée afterwards.
- Gaining the Will to Kill: Melinda decides to crash her car into Robert's trailer when she discovers him cheating on with Diana. In the film's climax, she makes her second attempt on both of their lives during their honeymoon.
- Green-Eyed Monster: Melinda becomes absolutely jealous of Robert after he begins dating and then plans to marry Diana. It's made evident during their final confrontation, as she claims his new lifestyle should have been hers.
- How We Got Here: The film opens with Melinda being reprimanded for refusing to adhere to court rulings, so she is mandated to attend therapy sessions where she is lead to recount how she ended up in that situation.
- I Can Change My Beloved: Melinda spends 18 years married to Robert, believing he would finally start providing for her knowing he is extremely reluctant to get a job and would rather work on his battery. Deconstructed in that she grows to resent him, which sows further seeds of discontent that ruin their marriage.
- Never My Fault: Melinda apparently doesn't even know the meaning of the word "accountability." Even from the beginning of her relationship with Robert, she irrationally blames him for dropping some notes she had for a college class by walking too closely to him and then runs off to let him clean up the mess.
- Never Trust a Trailer: The trailers make it seem like Melinda is wronged and pushed into retaliation. Admittedly, she is wronged at least once and Robert isn't as responsible of a husband as he should be, putting money into developing his battery rather than more stable income, but it becomes clear over the course of the film that Melinda has an undiagnosed mental disorder and slowly slips into irrationality from the stress of keeping that relationship long past it becoming untenable.
- Offscreen Teleportation: At the end of the film, Melinda manages to get onboard Robert's yacht without any explanation. Becomes even more ridiculous and contrived when she is knocked overboard, yet moments later, Melinda's back on the yacht without wet clothes or explanation how she climbed onto a moving ship.
- Poor Communication Kills: How the downward spiral begins. Roberts meets the women he cheated on Melinda with back in college, only now she is a top level employee at the same business Robert has been desperately trying to get to see his battery invention. When Melinda finds out, she assumes Robert is cheating again with the same woman and divorces him, and it only gets worse from there... for Robert.
- Protagonist Journey to Villain: Melinda is shown as a regular college student before meeting Robert, but over the course of 18 years, she eventually grows into a resentful and murderous woman.
- Reality Ensues: When Melinda rams her Jeep into the trailer where Robert is with Diana and knocks it over, she is in such a rage that she doesn't realize that she had been seriously injured and eventually passes out. Not only was her being the most physically injured of the three plausible (since a trailer has more protection than a Jeep), but the adrenaline of a high-pressure situation will keep a person going for a time even if they have fatal injuries.
- "The Reason You Suck" Speech: Melinda gives one to her sisters for putting doubt in her mind about Robert after his invention was accepted and he became a multimillionaire. She also breaks up with Devon and insults his manhood, making it clear that in her eyes, he will never be as ''good'' as Robert.
- Roaring Rampage of Revenge / Woman Scorned: The film basically builds up to this for Melinda.
- Sanity Slippage: By the time the film's climax rolls around, Melinda has clearly lost her marbles.
- Sassy Black Woman: Melinda tells her therapist that she is sick of the stereotype.
- Seven Deadly Sins: Robert's pride and Melinda's wrath drive much of breakdown of the relationship. Melinda's wrath is also what causes the climax of the movie.
- Unreliable Narrator: According to Melinda, Robert is a con man who was playing her from the start that wore her down over 18 years of shrewd manipulation. However, it's clear from her first meeting with him that although he is flawed, he is still well-intentioned and that she will be the main source of tension in their relationship, mostly from keeping it beyond all common sense.
- Unwitting Instigator of Doom: Melinda's sisters who kept telling her that Robert is worthless and using her when he was determined to get his invention noticed and wouldn't give up. It doesn't help that their words directly contribute to her Big Bad Slippage.
- Yandere: Melinda eventually becomes this to Robert.