As the curtains rise on another episode of "Miss Scarlet," Eliza Scarlet (Kate Phillips), accompanied by Clarence (Paul Bazely), Ivy (Cathy Belton), and Mr. Potts (Simon Ludders), sets out to celebrate Barnabas's ascension to the position of Chief Clerk. Their festive evening takes a turn when a waiter (Zeljko Maksimovic) approaches Eliza with a complimentary drink, a gesture courtesy of the Guild of Private Detectives. Drawn to their table, Eliza is formally introduced to Edmund Fletcher (Paul Lacoux), the Chairman, and Archibald Spilsbury (Ian Hughes), the Deputy Chairman. They reveal their intention to recruit Eliza, but first, they have a pressing concern involving Detective Inspector Alexander Blake (Tom Durant Pritchard). Edmund emphasizes the urgency, as Blake steadfastly refuses to collaborate with private detectives. He believes Eliza could be their secret weapon. Archibald underscores the need for impeccable repute in Blake's role, yet he has been in seclusion with Eliza multiple times.
Edmund proposes a scheme: Eliza must level accusations of improper conduct against Blake. Compliance would earn her a coveted spot within the Guild, complete with its perks. Eliza, however, steadfastly refuses.
Following this introduction, Blake encourages Sophia (Ruby Siddle) to embrace her school routine, unaware of her discomfort with the mean-spirited classmates. Meanwhile, Barnabas informs Ivy of his engrossing schedule, regretfully declining breakfast plans. Ivy, seeking companionship, invites Eliza but finds herself alone. Seeking clarification, Eliza confronts Blake about the Guild's intentions. She warns him of their relentless pursuit to undermine his authority. Blake, skeptical of her motives, questions her involvement. Eliza confesses that she was deeply insulted by their request to frame him falsely.
Undeterred, Blake confronts Edmund at the Guild headquarters. He declares his autonomy in running his division and dismisses any blackmail threats. Edmund reminisces about his tenure as Chairman and emphasizes the Guild's two thousand members, stressing his duty to uphold their prosperity. Blake remains unyielding. Edmund retaliates by hinting at dire consequences for Blake's daughter if he fails. Unperturbed, Blake announces his intention to hire a private detective, starting the very next day—Eliza, despite her non-membership.
Later, Blake assigns Eliza the task of conducting background checks for a new clerical position, including interviewing and evaluating candidates. He leaves the decision to accept or decline entirely up to her. Eliza embarks on her interviews, among them Cynthia Quinn (Rebecca Collingwood), venting her frustration to Ivy later that night. She scorns the menial nature of her new duties, to which Ivy responds by sharing her own experiences and encouraging Eliza to appreciate the opportunity to assist aspiring young women. Eliza notices Ivy's uncharacteristic demeanor and inquiries about her well-being, to which Ivy admits her confusion.
She laments that her days have blended into an endless sameness, prompting Eliza to inquire how she might brighten her spirits. Returning to the police station, Eliza seeks the counsel of Detective Fitzroy (Evan McCabe), who readily offers his help. Soon after, he receives a summons to meet Blake at 25 Girton Street. Eliza discovers that a body has been discovered at the Guild of Private Detectives, and together with Blake, they examine Edmund's lifeless form. Blake's demeanor darkens upon Fitzroy's arrival accompanied by Eliza. The detective mentions poisons, to which Eliza responds, noting the cloying sweetness in the air as a possible clue. She hypothesizes that Edmund was administered a substance via syringe. Noticing a shattered bottle of Chateau Lemaitre on the floor, Eliza remarks that Edmund was a teetotaler. Blake warns Eliza of contract termination if she doesn't focus on her designated duties.
Ivy collects sustenance from Arthur, feeling a pang of concern over her monotonous routine. Catching sight of a sign advertising for a secretarial assistant, she ventures inside only to be mistaken for a wanderer by a woman. The employer corrects her direction towards the butcher shop next door. Stepping outside, Ivy scrutinizes her reflection in multiple mirrors, pondering her future.
Clarence pays Eliza a visit, reassuring her that her current assignment is temporary. Eliza confides her aspiration to impress DI Blake. Clarence shares his findings from background checks, highlighting inconsistencies in Cynthia Quinn's employment history. The listed companies turn out to be fictitious, tracing back to Malone’s Investigation Agency. Intrigued, Eliza tails Cynthia, who leads her to Malone’s office. Peering inside, Eliza beholds Cynthia in conversation with Malone (Joseph May), a figure she recalls encountering alongside Patrick Nash before.
Blake interrogates Archibald, who refers to Edmund Fletcher as a friend. Archibald reveals he was with Edmund the night before in his office, discussing his re-election campaign, and departed at half-past eight. Blake inquiries about the broken wine bottle on the office floor. Archibald explains that Edmund abstained from alcohol due to a tremor acquired in Africa, exacerbated by even minimal intake. He can't fathom who might wish harm upon Edmund. With the election scheduled for the following evening but potentially postponed, Archibald considers stepping in to honor Edmund's memory and continue his legacy. Blake learns that Edmund had only one other candidate, who has been critical of his tenure.
At The Poisoned Parrott Inn, Eliza and Clarence discuss Thomas K. Malone. Clarence reveals that Malone had secured Nash's premises at a steal. Eliza suspects Malone's plan to install Cynthia at Scotland Yard to gain access to confidential information. Clarence adds that Malone intends to run for Chairman of the Guild of Private Detectives, deepening the intrigue surrounding the case.
Eliza engages Blake in a conversation about Malone and Cynthia, advocating for her accompaniment to confront Malone, an idea Blake vehemently opposes. She insists that her acquaintance with the man will facilitate their interaction, offering her assistance gratis. Blake, however, lays down strict instructions: she is to remain silent unless prompted, show no emotion, and take no action without his express direction.
Upon their arrival, Malone adopts a false identity, an act swiftly exposed by Eliza. They proceed indoors to delve into their discussion. Malone broaches the possibility of relocating and seizing the offices of Nash and Sons, dismissing his Guild membership as an unfruitful expenditure of time and resources. As he pours himself a drink, Eliza recognizes the wine as the same variety found in Edmund's office. Malone vehemently denies any involvement in Edmund's demise.
He reveals having spent two weeks in confinement following his last encounter with Eliza and claims to have been holed up in his office, crafting his election speech, the previous night, with his entire staff attesting to his whereabouts. Malone admits his dislike for Edmund Fletcher but maintains that Cynthia, though in his employ, operates independently of his directives. He suggests they ought to be questioning Archibald instead.
Outside, Blake and Eliza exchange a brief recap of their meeting. Blake intends to pursue alternate leads, granting Eliza leave to pursue her own ends. Eliza teases him about allowing pride to hamper collaboration, remarking that solving the case without him would be a mere formality. Blake reveals he has one last appointment before calling it a day.
Back at home, Eliza indulges in a game with Ivy and Barnabas while Potts reveals that Blake had inquired about the postmortem results of Edmund, mentioning Eliza's name in the process. Potts expresses surprise at Eliza not being a suspect and she probes further into the nature of the poison found in Edmund's system. Ivy's irritation at their squabbling prompts Potts to disclose it was Calabar Bean. Eliza is convinced that the puncture mark on Fleming's hand was administered by a syringe.
Clarence's arrival at the office prompts Eliza to share her latest revelation: the poison that ended Fletcher's life was both rare and ingeniously concealed. When administered through food or beverage, it acts slowly, taking hours or even days to manifest, ultimately causing death by cardiac arrest, indistinguishable from natural causes. Given Fletcher was poisoned by injection, his demise would have been swift. Eliza ponders the rationale behind such a choice, noting that Calabar Bean grows in the same region where Fletcher and Spilsbury once served in the military. Clarence expresses reservations about stepping on Blake's toes with their own investigation. Nevertheless, Eliza tasks Clarence with reaching out to an individual versed in the exotic reaches of the black market.
Clarence visits Mr. Gibson, offering inducements to learn about physostigma venenosum. Initially feigning ignorance, Gibson relents after Clarence buys off his bodyguard. Despite this, Gibson insists he has no dealings with poisons.
He refuses to return Clarence's money as well. As Archibald exits, Eliza slips into his office, her eyes scanning the room with curiosity. Blake eventually catches her red-handed within his sanctuary. Just before they hear a blood-curdling scream, Blake宣布他持有搜查令。 Downstairs, Malone is discovered bound and gagged. He narrates how Spilsbury lured him over, contemplating surrender. Over a drink, Spilsbury rendered him unconscious. Blake inquiries about the location of the voting. Following the vote, Archibald expresses his desire to validate himself in the eyes of all. Blake arrives shortly thereafter. Clarence confronts Gibson once more, revealing his alias among black marketers—Archibald Gibson. He aware that Gibson's spouse believes him deceased. Clarence attempts to coerce Gibson into divulging the information he had paid for the previous day. Gibson, seemingly unperturbed, asks for a pen.
Eliza ventures to Blake's abode and encounters Sophia. Soon after, Alexander welcomes her in, briefly discussing Sophia before probing into the information she possesses. Blake swiftly comprehends Eliza's relentless pursuit of the truth. They unanimously concur that Archibald Spilsbury is not the perpetrator. Eliza is privy to the identity of the individual who procured the poison that claimed Edmund Fletcher's life. Blake and his team proceed to apprehend Cynthia Quinn. At the precinct, Blake informs Cynthia of a syringe discovered among her possessions, its contents matching the poison that ended Fletcher's life. Cynthia maintains her innocence, explaining she worked for Fletcher, who tasked her with infiltrating Malone's circle. She elucidates Fletcher's deep-seated hatred for Malone and his desire for her to spy on him, albeit yielding scant information. However, she notes his daily indulgence in a bottle of wine. Cynthia confesses to having taken the wine from Malone's cupboard and procuring the poison for Fletcher, alleging he intended to inject it through the cork, simulating natural death. Due to Fletcher's tremor, he accidentally administered it to himself. Cynthia further alleges Malone's intent for her to infiltrate Scotland Yard, reporting back on confidential cases.
Eliza confers with Blake, who finds Cynthia's narrative plausible. He commends Eliza for her diligence. Eliza presents him with a copy of "Alice's Adventures in Wonderland" for his daughter. Blake shares that Sophia has been struggling to adapt to her new environment, leading to discord between them, resulting in her staying with their neighbor, Mrs. Bambury. Blake's wife passed away a few years prior. Fitzroy interrupts to announce the clerical officer is prepared. Eliza asserts confidence in her selection of candidates, highlighting Ivy's secured position.
