As the curtain draws on the finale, Eliza Scarlet (Kate Phillips) steps back into her abode, only to be confronted by a mysterious package resting before her threshold. With curiosity piqued, she cautiously carries it indoors. Shortly thereafter, Patrick Nash (Felix Scott) bursts in, urgently warning her against uncovering its contents. They gingerly place it on the desk, where Patrick, with a sigh of relief, lifts the lid and mutters a grateful prayer. He clarifies that the device poses no immediate threat, its timer disconnected from the detonator. Eliza learns that Moses (Ansu Kabia) has also been the recipient of such a perilous gift. Patrick and Moses propose a private investigation, but Eliza, undeterred, insists on consulting with The Duke.
Upon revealing his own receipt of a bomb, The Duke (Stuart Martin) unveils a chilling revelation: William knows precisely who is orchestrating this macabre spectacle. He elaborates that while all of them have been targeted, he stands as the primary mark, his package accompanied by a note in Irish Gaelic that chillingly proclaims, "We are watching you." The Duke warns that the Irish home rule movement has transcended mere politics, with radical factions resorting to armed conflict. Over the past year, bombs have been planted in barracks and governmental strongholds alike.
Eliza reminds them that Moses has been entangled in the professional web spun by Nash, who in turn has served under William multiple times this year, perhaps offering an inkling as to why Moses has also been ensnared. Realizing the gravity of the situation, William promptly contacts the Special Irish Branch, summoning the head of investigations to their aid.
Arthur St John Hudson (Sam Hoare) enters the fray, his keen eyes absorbing every detail of the bombs and their accompanying message. He asserts the need to establish a clear chain of command before proceeding further. Hudson makes his intentions unmistakably clear: from this moment onward, he will assume full control. While acknowledging the need for cooperation, he stresses that they will operate under his directive, reluctantly invoking his superior rank, an order directly stemming from the Home Secretary himself. He acknowledges the awkwardness, given their recent competition for the same position, expressing hope that any lingering resentment over his selection will not undermine their mission.
William is entrusted with overseeing the gathering of the devices, while Hudson embarks on a mission to interrogate individuals. Hudson sits down with Eliza, probing into the reasons behind her being targeted. She clarifies that her rapport with the inspector is strictly professional. When Patrick's turn comes, he concedes that Eliza is indeed competent. Despite his Irish heritage, Patrick vehemently denies any involvement, asserting his innocence.
Moses informs Hudson of his birthplace, The Parish of Manchester in Jamaica, but remains tight-lipped about the duration of his stay in the country. Hudson demands a roster of those who have hired Moses, to which both Moses and Eliza respond by asserting that he is barking up the wrong tree. Eliza suggests that Hudson should instead concentrate on why the bombs weren't timed to detonate. Hudson ponders over the possibility of it being unintentional, recalling numerous past instances where their bombs failed to explode. He rejects Eliza's request to investigate by suspending her license, leaving her to vent her frustration to Moses. Moses acknowledges that things are far from ideal, sharing how a series of events compelled him to flee Jamaica years ago. Though he had intended to keep moving, he has found himself rooted in London for the past three years. He doubts that his pursuers are behind the bombs but is more concerned about Hudson's inquiries potentially leading to his whereabouts being discovered. Hudson might send a telegram to Jamaica with a description of Moses, sparking rumors of his whereabouts—a scenario Moses deems perilous.
Eliza visits her business only to find a notice ordering its closure affixed to the door. She tears it down and steps inside. Patrick catches up with her, revealing that his place was also ransacked, and his license suspended too. He asks if she's heard about the train robbery that occurred last Thursday on the Great Northwest Line, traveling from London to Liverpool. Eliza mentions the Jewel of the North, and Patrick reveals he offered his services because the train company is dissatisfied with the handling of the case.
The train robbery bears striking resemblance to another heist orchestrated by Irish nationalists in Bristol mere months prior. Certain factions have resorted to criminal activities to finance their agendas. Patrick harbors suspicions that someone intends to deter them from delving deeper into the investigation by instilling fear. Having been transferred to Scotland Yard a few days ago, William is now at the helm of this case. Patrick subtly hints that Eliza might be on his payroll, exploiting the fact that women are seldom perceived as undercover agents to gain their trust and potentially their business. When Eliza inquiries about the frequency of his deceitful assertions, Patrick counters by saying he wouldn't need to resort to lies if she decided to join his ranks. He contends that they ought to uncover the mastermind behind these incidents independently.
Fitzroy (Evan McCabe) informs William that Hudson is deploying additional reinforcements. He also possesses a container brimming with dossiers on suspected Irish extremists, as Hudson has mandated his assistance in the investigation. Hudson alerts William that they anticipate more attacks in the near horizon, prompting an expansion of their operational scope. William reminds Hudson that he and his team have their own tasks at hand. Upon visiting Eliza, who is engrossed in cooking, William reveals that he has been instructed to take a temporary leave of absence. He proposes collaborating on the case.
William soon discovers that Eliza is already working alongside Patrick and Moses on the bombing and train robbery case. Moses enlightens everyone that the "Jewel of the North," a daily service connecting London Euston to Liverpool Lime Street, typically ferries passengers and mail. However, on the day of the robbery, it carried something unusual: a substantial sum of money dispatched by the Great Northwest Railway Company to a construction site near Liverpool. This money represented the wages for hundreds of newly hired workers tasked with building new railway lines across the northwest. The robbers struck during a prearranged stop.
Someone undoubtedly needed to be privy to the train's stopping schedule, necessitating a compilation of staff members' details. In light of this, Patrick, still employed by the railway corporation, was dispatched to headquarters alongside Moses. Meanwhile, Eliza and William set off for the bank that disbursed the train company's wages. As they departed, their conversation veered towards Arabella. William mentioned her well-being, hinting that Eliza would know firsthand if she had accepted Arabella's dinner invitation. Eliza replied that she was genuinely happy for them but had declined due to her hectic schedule.
At the bank, they spoke with James Bamford (played by James Barriscale), who personally oversaw the money delivery. He assured them that nothing suspicious had transpired and the funds had been delivered without incident. Eliza revealed that Mr. Basil Sinclaire was a close confidant and feared he might shy away from negative publicity. James agreed to furnish them with a roster of employees who were on duty during the robbery.
Upon arriving at headquarters, Moses and Patrick discovered that yet another bomb had been delivered to Enoch Lyndhurst (played by Paul Putner). Despite scrutinizing the list of personnel from both the train company and the bank, they unearthed no useful leads. When William mentioned his dinner plans, Eliza urged him to proceed without delay. Patrick jestingly speculated that William was late for his romantic rendezvous, but Eliza feigned ignorance. Moses, contemplating his future, mentioned that Nash was establishing an office in Paris and had offered him a position. Unsure of his decision, he also proposed taking the bomb to Solomon (played by Brian Bovell) for examination.
During Solomon's inspection, Moses confided in Eliza about the job offer. Solomon, however, doubted the involvement of the Irish Republicans, citing the bomb's sophistication and military-grade nature. Elsewhere, William apologized to Arabella (played by Sophie Robertson) for his tardiness. She gracefully dismissed it, emphasizing their presence in the moment as what mattered most. As they sipped wine, Arabella learned of William and Eliza's collaborative efforts.
It dawned on her that perhaps he had lost interest in her, despite William's assurance that such a notion was worlds away from the truth. As they set the table for their meal, William shared with her Eliza's unwavering determination and her attempts to master the art of cooking. The following day, William offered to return to duty to lend a hand with the ongoing investigation. Hudson, however, declined his offer, believing it safer for William to remain distant from Scotland Yard's tumultuous affairs. Pretending to take a sip from his drink, he bid farewell and stepped outside, where he entrusted Fitzroy with a key, instructing him to procure records of convictions pertaining to individuals or gangs versed in explosives. Additionally, William requested case notes from the train robbery, which he later handed to Eliza, mentioning an interview with the porter who was on duty that fateful day. Intriguingly, the porter recalled five men delivering the money, contradicting Bamford's earlier statement of only four.
When confronted, Bamford dismissed it as a mere slip of the mind. William's inquiry about the missing man named Jack Fenton prompted Eliza to reveal Jack's criminal past, which included convictions for armed robbery. Pressured further, Bamford reluctantly admitted that Jack was his brother-in-law, a former soldier discharged dishonorably and later incarcerated in Newgate. Bamford was unsure of Jack's involvement in the robbery or his current whereabouts but had heard whispers of him occasionally working at a jewelry store in Hatton Garden.
Eliza swiftly dispatched a message to Nash, tasking Moses with initiating the search for Jack. They devised a plan to visit the jewelry shop, hoping to catch a glimpse of Fenton. Posing as an engaged couple, Eliza inquired about engagement rings, subtly probing for information on upcoming deliveries. Meanwhile, Patrick and Moses stationed themselves at a nearby pub, keeping a vigilant watch for Jack's arrival. When a man matching Jack's description entered, tensions flared, culminating in a heated altercation.
As the police approached, the man hastily bolted, abandoning Moses and Patrick to their fate, where they were promptly apprehended. Fitzroy, with a sense of urgency, broke the news to William and Eliza, adding that Moses had mentioned they had stumbled upon someone they had been actively seeking. Just as Fitzroy departed, Enoch arrived, his eyes scanning the room until they landed on Eliza. He confided in them, expressing his belief that this particular heist bore a distinct and unsettling resemblance to none they had encountered before. That very morning, he had discovered from the chief conductor of the Jewel of the North that he had a peculiar encounter with a man in a local tavern days prior to the robbery. The conductor had been invited to this man's humble abode—a room perched atop a shop—where they indulged in libations. The stranger, who introduced himself as Jack Fenton, inquisitively delved into the details of train schedules and signaling.
Eliza inquired about an address, her curiosity piqued. While they inspected the flat, Eliza confided that her preferences in jewelry leaned towards modest tastes. For her, the joy of Christmas lay in the ritual of unwrapping gifts, rather than the presents themselves. She speculated that Arabella might hold a different perspective. Meanwhile, William's discovery of another bomb interrupted their conversation, as he tried, albeit unsuccessfully, to persuade Eliza to evacuate. Stubbornly, she refused, her recent readings on explosives giving her the confidence to possibly defuse it. With deft precision, she severed all three wires, saving William from impending danger.
They conjectured that the bomb's detonation had been intended. The stick of dynamite bore the manufacturer's name—Galton and Hobbs. Seeking answers, Eliza visited Enoch, querying him about the company's expansion northwest and their use of dynamite for tunneling. She revealed her earlier visit to Galton and Hobbs, commending their cooperativeness. Aware of Enoch's oversight of explosives procurement and transportation, she suspected he might know Jack Fenton. William's entrance, clutching Corporal Fenton's discharge sheet, was a strategic maneuver to coax Enoch into talking. Their shared history in the First King's Dragoon Guards served as a bridge between them.
Eliza inquiries whether he might have orchestrated the bomb delivery to himself, aiming to implode their acquaintances in Fenton's modest abode. Enoch retorts, insisting he harbored no intention to cause harm, laying the blame solely on Fenton's shoulders. The bombs dispatched were dummy devices, intended solely to mislead. They subsequently escort him to Scotland Yard for further questioning.
William harbors suspicions that Enoch's motive was financial gain, believing a man of his stripe would confess all to avert the specter of incarceration. He vows to secure the release of Moses and Patrick, acknowledging the intricate dynamics between them but expressing a longing for Eliza's companionship. Despite understanding her affections towards Arabella, William expresses hope their monthly dining ritual can persist, prompting Eliza to ponder Arabella's reception of this arrangement.
Upon entering, William informs Hudson that his duties in this matter are concluded. Meanwhile, Eliza discovers Fitzroy engaged in training with Moses and apprises him of the arrests, presenting him with a French dictionary. Moses confesses his Parisian yearnings, hinting at potential temporary employment in the city. When Eliza expresses her numerous desires, Moses gently urges her to focus on one aspiration.
William's tardiness prompts Arabella to confront him, sharing her past marred by a father incapable of love and a husband whose sole pursuit was wealth. She speculates Eliza's influence delays him, questioning his assertion of platonic friendship and accusing him of being enamored with her unless proven otherwise. Arabella warns of Eliza's ambition overshadowing all, even her feelings for William.
Eliza discovers a stash of business cards on her desk, prompting a confrontation with Patrick. He unveils plans to establish a Parisian branch, necessitating someone to oversee the London operations. He offers her a pivotal role, where she can select cases and clients, leading a team of twenty. He emphasizes the symbolic impact of a woman helming such a significant agency, contemplating an office bearing her name. Patrick has already made provisions for this. As the episode draws to a close, Nash inquiries whether they have struck a deal.
