Patience Evans (portrayed by Ella Maisy Purvis) delicately places her notepad atop a polished table and sets the timer on her wristwatch with meticulous care. Inside the Royal Northern Bank, Dr. Aadesh Chopra (embodied by Deepak Verma) attempts to retrieve funds from an ATM, only to encounter a stark denial of the transaction. Meanwhile, Patience immerses herself in a challenging puzzle, her mind elsewhere yet focused.
Chopra then steps forward to the bank teller's window, politely requesting a withdrawal of 8,000 pounds. Unbeknownst to him, Patience continues her mental jog with the puzzle pieces, her concentration unbroken. Upon exiting the bank, Chopra ventures into the street, almost colliding with an approaching vehicle whose driver honks in protest. Undeterred, Chopra crosses, oblivious to the world around him.
Still engrossed in her puzzle, Patience remains unperturbed by the unfolding drama outside. Chopra, however, makes a curious move—he deposits the envelope containing his hard-earned money into a nearby trash bin. He ambles towards his car, retrieves a petrol can from the trunk, douses himself liberally, and, in a harrowing act, ignites himself into flames. At precisely this moment, Patience halts her timer, lays aside the puzzle, and jots down "15:38" on her notepad with deliberate precision.
Detective Inspector Calvin Baxter (played by Mark Benton) requests that Detective Inspector Bea Metcalf (Laura Fraser) revisit Chopra's case file. She summarily dismisses it as a "death by misadventure." Baxter reveals a wrinkle in the case—the Chief Constable's husband was a bridge partner of Chopra's. Detective Sergeant Jake Hunter (Nathan Welsh) and Metcalf scrutinize CCTV footage, which unequivocally shows Chopra immolating himself with no one in proximity. Hunter concludes it's a shut case. DC Will Akbari (Ali Ariaie) is left with the tedious task of sifting through 90 hours of CCTV footage.
Flashing back, a toddler Patience (Oona Van Harneveldt) watches in awe as Mathilde Evans (Lotte Lauren) plays the piano, a scene of innocence and wonder. Switching to the present, at a bustling bus stop, a man (Nathan Graham) boldly attempts to court Patience, inviting her for a drink. She politely declines but, ever considerate, offers her phone number before boarding a waiting bus, leaving him with a glimmer of hope.
Upon her arrival at the morgue, Metcalf discovers Prisha Chopra (Rekha John-Cheriyan), tears streaming down her face as she mourns over the lifeless body of Chopra. The mortuary assistant, Martin Crasborn, informs her that Dr. Loretta Parsons (Liza Sadovy) is currently at lunch. Prisha confides in Metcalf, revealing that Chopra was a renowned psychiatrist who had weathered a personal crisis years ago but had been radiantly happy in the past year, even contemplating an early retirement. She also mentions an inexplicable 8,000-pound withdrawal that has mysteriously vanished.
Upon reaching the City of York Police Department, Metcalf unwittingly crosses paths with Patience, who is making her entrance into the Criminal Records Office. Patience meticulously arranges her food bowls in the refrigerator and sets her desk in order, preparing for her workday. Inside, Metcalf inquiries Hunter if he remembers the psychiatrist who took his own life at the hotel near the station. Hunter responds by recounting that Neal Jamieson, the deceased psychiatrist, was retired and the hotel in question was far from new.
Metcalf peruses Jamieson's case file, uncovering that he withdrew 6,000 pounds mere hours before his estimated time of death. He recalls the tragic scene of Jamieson slitting his wrists in a bathtub, having become a father just 24 hours prior to his suicide. As Patience hands Metcalf Jamieson's file, she cannily points out the mismatch in her socks. Realizing it's the incorrect file, Metcalf seeks assistance from her officious colleague, Sharon Verdegem, who proves unhelpful. Desperate for answers, she sneaks into the Criminal Records Office to consult with Patience about Dr. Brendan Clark's (Joseph Arkley) file.
Patience reveals that there are striking similarities between Jamieson's and Clark's case files. She adds that Clark, a child psychiatrist, also made a substantial cash withdrawal shortly before taking his own life. Intriguingly, Chopra, Clark, and Jamieson all passed away on a Friday, the fourth day of the month.
Metcalf informs Baxter that Clark has inked a lucrative book deal, granting him ample motive to lead a lifestyle akin to Chopra's. She urges him to close the Chopra case, yet Baxter counters by reminding her that the bank manager insisted Chopra seemed intoxicated. In a flurry, Metcalf, having forgotten to pick up her son, Alfie Metcalf-Hayes (Maxwell Whitelock), dashes to the school, only to discover that David Haynes (Eddie Elks) had already beaten her to it. Miss Page (Shireen Farkhoy), insistent on addressing Alfie's disruptive conduct, presses Metcalf to reschedule a meeting, noting her history of missed appointments. David chides her, his sarcasm sharp, hinting at the reason he holds custody.
Elsewhere, Patience rehearses her words, preparing to confront Metcalf about the case file. Alfie, sensing his mother's distraction, inadvertently knocks her phone from her grasp. When Patience finally manages to call Metcalf, her nerves cause her voice to falter, and she abruptly terminates the call. Alfie stubbornly refuses his hamburger, citing an aversion to pickles.
Meanwhile, Douglas Gilmour (Adrian Rawlins) warns Patience that her boss, Alistair John Maynard, has been informed of a colleague's complaint about her meddling in an investigation. She defends her actions as part of her job, but he expresses concern over her potential entanglement in the case and her ability to cope.
Upon her arrival at the police station, Metcalf encounters Patience, who lambasts her for tardiness before commending her 71.3% clearance rate. Handing her a case file, she inquiries whether Chopra was intoxicated. Metcalf scans the document as they step into the elevator, with Patience trailing behind, only to exit abruptly due to overcrowding concerns. She later finds Metcalf poring over the file at her desk, which is intricately linked to Clark's case.
Metcalf queries whether Clark received his book proofs via courier an hour prior to his demise. Patience reveals several instances where individuals were influenced by scopolamine, a tropane alkaloid inducing psychosis. Metcalf notes the absence of this in Clark and Jamieson's postmortem reports, to which Patience responds that both men were deceased for four days before toxicology tests were conducted, and scopolamine becomes undetectable after 72 hours. Metcalf insists she inform Parsons of this new information.
At the morgue, Parsons presents them with the toxicology report, confirming no trace of scopolamine. Patience explains that its half-life is nine hours, and in most cases, it is inhaled, thus detectable in the respiratory tract, painting a clearer picture of the mystery surrounding Clark's death.
Metcalf delves into the discovery of scopolamine in Chopra's respiratory tract with her team, sparking a sense of urgency among them. Patience, growing increasingly anxious, is plunged into a nostalgic whirlwind, recalling a harrowing encounter during a visit to Dr. Clark. George Evans (played by Jamie Maclachlan) reveals his fascination with her involvement in police work, unaware of the turmoil within her. Clark labels her condition as early-onset pediatric schizophrenia and advises psychiatric hospitalization, solemnly informing George that independence and societal contribution might elude her forever. Snapping back to the present, Patience abruptly rises and exits the room.
After wrapping up her shift, Metcalf escorts Patience to her destination but discreetly tails her to an autistic support group meeting. Meanwhile, Billy Thompson (Connor Curren) inquires about Maya's (portrayed by Divya) work challenges. Maya confides in him, sharing how she seeks solace in the restroom to stave off emotional meltdowns. Theo (Lewis Ian Bray) echoes similar experiences of workplace ostracism. Billy boasts of his finance degree from Open University, prompting Maya to ponder whether she should disclose her autism to her colleagues. Josie (Madeleine Bowyer) contributes her own story, revealing that her son has shuffled through five schools in six years.
Metcalf reflects on a photo of Alfie stored on her phone, later observing him engrossed in a video game at home. In a cozy moment, Patience hugs her bearded dragon and cat, while Metcalf attempts to solve a nine-dot puzzle with Alfie's helpful input. In a conversation with Hunter, Metcalf learns that Baxter is displeased with her decision to involve Patience in the case without prior consultation. He disputes her inclusion, emphasizing her civilian status. Metcalf counters, reminding him of Patience's crucial connection between the cases.
The hotel manager (played by Sarah Gallagher) dismisses any unusual behavior by Jamieson and speculates he might have missed his train. Metcalf and Hunter inspect Jamieson's former hotel room, where Metcalf notices a cigar beside the bathtub amid the grim scene of blood. A housekeeper, Yemaya Vasquez (Joana Borja), enters abruptly with a cart, catches sight of them, and hastily exits. The hotel cleaner supervisor (Lucy Brownhill) enlightens them about Yemaya discovering Jamieson's body and her expired visa.
Later, Naomi Jamieson (Beverly Longhurst) confides in Metcalf about their unexpected pregnancy with Martha after giving up on having children. She reminisces about her husband's ecstatic reaction upon Martha's birth. In a separate phone call, Metcalf discloses Jamieson's sex addiction and the STD he transmitted to her. At the police station, Hunter informs Metcalf about CCTV footage showing Patience on the rooftop, 36 hours post Chopra's suicide. She passionately defends Patience, revealing her tragic misdiagnosis by Clark during childhood. The footage captures a distressed Patience seated in the interrogation room, her vulnerability palpable.
