As the curtain rises on the premiere episode of "The Ex-Wife," Tasha (portrayed by Celine Buckens) cruises in her vehicle, her voice echoing through the narrative as she declares that from our very birth, we're sold a fallacy—that people are inherently good or bad. Beside her, a figure materializes: Jen (played by Janet Montgomery). Tasha contends that no such dichotomy exists; everyone harbors the noblest of intentions. The tension escalates as they engage in a perilous game of vehicular chicken, culminating in a collision just as Tasha utters, "Love can sanctify nearly any act, driving us all to commit horrors." She glances back as rescue efforts commence, pulling Jen from the wreckage mere moments before an explosion engulfs the scene.
Three months prior, the domestic scene shifts to Tasha and Jack (embodied by Tom Mison) preparing for an intimate dinner. Jack's phone rings, Jen on the other end, imploring him to impart some news to Tasha. Yet, mindful of their wedding anniversary, he declines. The conversation ends abruptly, Jack dismissing the matter with a cryptic, "You wouldn't want to know." He diverts the topic to their slumbering daughter, Emily, while Tasha's curiosity piques regarding Jen's urgent message. Jack reveals Jen's call concerned his sister Hayley (Clare Foster), who wishes for Jack and Jen to serve as godparents to Ethan. Tasha will be Auntie Tasha. Jack further shares that Jen and Hayley's bond spans two decades. As a pleasant surprise, Jack erases Tasha's student loan debts, despite knowing she disdains charity.
Transitioning to post-prologue, Jack gripes to his attorney about the latter's ineffectiveness, while Tasha cradles their infant. Jack laments his inability to even chauffeur his family home. They agree to proceed with their climbing expedition as planned, prompting Jack to call Lola (Nina Singh) to arrange an office pickup, his driving privileges revoked for three years. Arriving home, Tasha's enthusiasm wanes upon learning Jen's arrival. Descending the stairs, she interrupts their discussion about the vintage wine Jen has brought for Jack. Jen learns of Jack's driving ban and Tasha's lack of a license. Tasha proposes the train for the christening, but Jen, loathing trains, offers to chauffeur them all, her vehicle spacious enough.
During the journey, they reminisce about Jen's own christening at the same church. Tasha's attention wanders from the rear seat, her mind drifting to a flashback. Cycling, she receives a call from Sam (Jordan Stephens), inquiring about her post-interview status. Disheartened by radio silence, she cycles onward but soon collides with Jack's car, toppling off her bike. Jack rushes to her aid, ensuring she's unharmed. Once upright, Tasha checks her phone while Jack fetches her water. He offers to call her workplace, excusing her tardiness, and volunteers to drive her home, attend to her wounds, fix her bike, and ensure she returns via taxi. Arriving at her place, he assists in cleaning her scrape and serves her tea. As a gesture of goodwill, Jack hands her 400 pounds for a new bike, the air thick with unspoken possibilities.
When she brings up her newly refurbished phone, they come to a consensus that a sum of 800 should suffice for all expenses. As he attends to her wound with tender care, their conversation drifts to his wife, Jen. Later, while at work, Jack calls Tasha to inquire about her wounds, and they decide to have an early dinner together later in the evening. Prior to discussing Jen and her passion for interior design, Jack inquiries about Tasha's graphic design pursuits. When Tasha casually asks about children, Jack explains that they face a challenge as Jen is infertile. He hesitates to overwhelm her with their personal struggles, emphasizing their long-standing relationship and the many hurdles they've overcome together. Despite his best efforts to make Jen happy, life hasn't always cooperated. Jen has agreed to a trial separation, albeit only involving separate rooms for now, as they both seek clarity on their future. Unexpectedly, Jack finds himself sharing an intimate moment with Tasha.
Moments later, Tasha confides in Sam, revealing that the encounter was three months ago and apologizing for keeping it from him. She has taken numerous pregnancy tests, and the results are positive. Aware that the child isn't Sam's, Tasha intends to terminate the pregnancy. During a subsequent meeting with Jack, she informs him of her decision to visit a clinic, but he persuades her to reconsider. Meanwhile, Tasha sits in the background as Jack and Jen participate in their baby's christening alongside Hayley. The group later attends a party, where Tasha and the others indulge in alcoholic beverages. Hayley captures photos of Jack and Jen with the baby, and as they step outside to review them, Jack expresses gratitude to Tasha for her understanding. Tasha jests that Jen behaves as though she's still Jack's wife, playfully suggesting they might mistake her for the nanny, before accusing Jen of deliberately choosing her as the godparent. Hayley interrupts, requesting they settle their differences elsewhere.
Once they're alone, Tasha confides in Hayley that while Jack is fine, she finds it difficult to navigate her presence alongside Jen. Hayley reminds her that it's merely a party and suggests, perhaps tactlessly, that it might be better if Tasha abstained from attending future gatherings. Tasha curses at her, prompting Hayley to label her actions as classless. Hayley proceeds to remind Tasha of how she arrived in their circle and how Jack and Jen struggled for years to conceive. Now, conveniently, she finds herself pregnant. Hayley asserts that though Tasha may have gotten everything she desired, she doesn't get to dictate her friendships. Jack returns to check on them, inquiring about the altercation. Tasha insists that it must stop and proposes that Jen refrain from visiting their house, as her presence makes things awkward for her and Emily. Jack agrees to speak with Jen.
Later that night, Tasha shares something Hayley said earlier, prompting Jack to assure her that she'll learn to ignore such comments in time. When Tasha reveals Hayley's accusation that Jack, rather than Jen, had fertility issues, Jack confirms it, humorously likening his sperm to numerous swimmers, albeit not all Olympic-caliber. It was challenging, yet not entirely insurmountable. Jack alleges they could have continued trying, but Jen decided to halt their efforts.
He endeavors to articulate the reasons behind his silence, leaving Tasha in the dark. A short while later, Tasha sends Sam a heartfelt message, expressing her longing for their conversations, and he reciprocates her sentiments. Conceding, he apologizes for his earlier words. While on a shopping spree, Tasha unexpectedly encounters Jen, who confesses she traveled a long distance to this particular store, driven by her routine-bound nature. As an assistant approaches to assist Tasha, she entrusts Emily to Jen's care. Upon her return, Emily's absence plunges Tasha into a panic, prompting her to search frantically for her daughter. Her relief is palpable when Jen appears behind her, cradling the baby. Jen insists she merely stepped into another aisle for bread, yet Tasha remains unsettled.
Back at their abode, Tasha scrutinizes Jen's profile, uncovering photos of her with Jack. Her surprise intensifies when Sam enters the room unannounced. Their brief exchange with Jack, who soon departs, leads Sam to reveal the purpose of his unexpected visit. Tasha cautions him that Jack is far from naive and is aware of his dislike. She contends that a simple text before visiting would have been considerate. Sam suggests she venture out more often, arguing that Jack doesn't harbor resentment towards the rivalry. He jokes, lightening the mood, that it could have been worse – her ex-husband making an appearance. Curious, Sam inquires about the perks of wealth before Tasha agrees to showcase her luxurious handbags.
The following day, Jack remarks that Sam's reservations towards him persist. Tasha concedes they're working on mending their relationship and appreciates seeing a familiar face. She clarifies that while Sam is protective, he doesn't hate Jack. Jack reveals they're urging him to visit New York next week, despite its inconvenience. He offers to procure tickets for Tasha and Emily if she hesitates to stay behind alone, but Tasha is reluctant to subject their daughter to a lengthy flight so soon. She's indifferent to Jack's trip, however. He mentions having spoken to Jen, ensuring she won't revisit. Sam proposes taking Tasha somewhere, needing to retrieve Emily's rabbit from the house. With a hint of mischief, he suggests he might borrow something else while he's at it.
They engage in heated discussions about Jack's frequent absences, which deeply troubles Tasha as she feels his absence keenly. The conversation then drifts to Jack's occupation and Tasha's aspirations, but she hesitates to depart just yet, sensing that the timing isn't quite right. Upon returning to her abode, Tasha is taken aback to find Jen perched in her kitchen, sipping from her wedding wine.
With stern determination, Tasha asserts that Jen cannot just barge in and threatens to call the authorities. Jen, however, explains that Jack entrusted her with a spare key for emergencies and that she desperately needed to access some crucial documents. Jack had authorized her to enter if Tasha wasn't home. Jen confides in Tasha about her dire financial woes, revealing that HMRC has slapped her with a whopping tax bill. Their chat briefly touches upon Tasha's friend with the car, prompting Jen to caution her about Sam, hinting at Jack's volatile temper. Tasha warns Jen of informing Jack about her unauthorized visit, causing Jen to hastily agree to leave. As she exits, Jen mentions Sam again, claiming Jack brought him up after the christening, but Tasha is skeptical of her story.
Suspecting Jen might have followed her to the supermarket, Tasha demands the return of the keys as Jen prepares to depart. She firmly tells Jen to cease her intrusions and leave them in peace. Jen implores Tasha to convey to Jack that she can no longer endure this situation.
Upon Jack's return, Tasha recounts the entire ordeal and Jen's revelations. Jack admits he asked Jen to come over but expected her to knock. He confesses that Jen is distressed about the tax issues, though Tasha remains unconcerned. She suspects Jack is lying or that Jen has been covertly monitoring their home. Jack assures her he'll talk to Jen again, emphasizing that it must cease. He warns that if it doesn't, they'll have to address it more stringently, even considering police involvement if she feels unsafe.
The next day, Jack leaves for work. Tasha sends a text to Sam, inquiring if he's ever encountered Jack's ex, to which he responds negatively. She invents an illness in her mother to secure Anna's babysitting services for Emily. Disguising her true intentions, Tasha ventures out, tracking Jack's phone. She parks her car short of the destination and manages to sneak into the complex and the building. With a sense of urgency, Tasha knocks on an apartment door, leaving Jen and Jack utterly astonished to see her standing there.
