Episode 4 of *House of Guinness* opens with the grand wedding of Arthur and Olivia. Amidst the festive revelry, Aunt Agnes and Anne embark on a mission to scout potential brides for Edward, who stands next in line for matrimony. As the music swirls and dances unfold, Benjamin Jr., now a captain in the Dublin Army, attempts to approach Lady Adelaide on Edward's behalf. However, Lady Adelaide firmly rejects Edward's proposal and sends Benjamin Jr. packing.
On his way back, Benjamin Jr. encounters Lady Henrietta, who takes the initiative to introduce herself. Christine, witnessing this exchange, is left heartbroken. Later, Benjamin Jr. confides in Aunt Agnes, revealing his love for a maid and his desire to marry her. Aunt Agnes, resolute in her stance, refuses to allow him to wed a mere maidservant. She concedes only on the condition that his annual income is raised to £4,000 a year, at which point she will choose a suitable bride for him.
Arthur and Olivia, meanwhile, ponder over Edward's plight, noting how unaccustomed he is to rejection and speculating whether he will pursue Adelaide relentlessly. Elsewhere, Sean meets Anne, who is making her exit from the party after a clumsy tumble on the dance floor. Anne confides in Sean about her recent miscarriage, but Sean responds with indifference, urging her to move past him. Anne expresses her need for someone dependable, yet ultimately departs with her husband.
In a moment of solidarity, Olivia stands up for Arthur in front of Sean, much to Arthur's surprise. He is taken aback to discover that Patrick and Ellen were also invited to the wedding. Demanding their departure, Arthur is met with Edward's intervention, who pleads with his brother to show respect towards Ellen, whom he sees as a valuable ally for the future. Edward and Ellen then proceed to convince Arthur of the mutual benefits that a Guinness-Fenian partnership would bring. Arthur, feeling betrayed by Edward's actions, is left with no choice but to reluctantly acquiesce in order to safeguard his secret.
Meanwhile, Reverend Henry confronts Edward about his controversial alliance with the Fenians, but Edward, still reeling from Adelaide's rejection, is too consumed by his own turmoil to heed the warning.
Simultaneously, Byron arrives in New York and crosses paths with his cousin, William. William comes to the Irishman's rescue, shielding him from a violent attack waged by local Fenians who harbor animosity toward all Irishmen and Catholics. Sensing an opportunity, Byron invites William to sample a pint of Guinness Beer, painting a vivid picture of the lucrative prospects that a partnership with Guinness could bring in the days to come. Intrigued, William agrees and extends an invitation for Byron to stay with him temporarily.
Two months slip by, and the Dublin elections loom on the horizon. Anne makes her way to the brewery, her heart set on meeting Edward, only to bump into Sean. With a mischievous glint in her eye, she playfully teases Sean about his single status, while Sean, with a protective air, assures Anne that he'll always be there to catch her if she ever falls.
Seizing the moment, Anne engages Edward in a conversation about his involvement in Arthur's election campaign. Edward, preoccupied with expanding the business, shares his preoccupations. Anne, however, drops a bombshell: she's uncovered evidence that Arthur is attempting to sway the local populace by offering them £5 for each vote cast in his favor. She implores Edward to intervene and halt Arthur's schemes, accusing Edward of neglecting his brotherly duties.
Feeling betrayed, Edward points the finger at Sir Benjamin, blaming him for the wreckage of his life, as he sets out to confront Arthur. In a cunning move, Edward bribes Bonnie to divulge Arthur's current whereabouts. There, in the heart of the apartment, Edward confronts Arthur head-on about the ballot fraud, demanding to know the mastermind behind this deceitful plot.
A heated argument ensues between the two brothers, but amidst the tension, Arthur introduces Edward to his accomplice, Arty. Reluctantly, Edward escorts Arthur back home, where the siblings engage in a heartfelt conversation about Arthur's actions. Olivia, ever the defender, stands up for Arthur in Edward's presence. Edward, consumed by frustration, spills the beans about Arthur's involvement in the scam, bringing the episode to a dramatic close.
