The fifth episode of "Sherlock & Daughter" kicks off with the exciting installation of a novel telephone at Sherlock's abode. As the technicians work diligently, Sherlock's trusty assistants arrive with a bombshell: they've tracked down Michael Wylie and are ready to escort him to Sherlock's doorstep.
The trio makes their way to a quaint tea shop, where Sherlock interrupts an intense spat between Michael and Amelia. Amelia is in full throttle, branding Michael as a Moriarty in disguise. Without missing a beat, Sherlock whisks them back to his home and demands an immediate explanation from Michael.
Michael unfolds his tale of woe, recounting how he was adopted by a nefarious band of thieves following his mother's demise. His criminal career was cut short when he was apprehended and shipped off to Australia to serve another family. Fourteen long months later, he broke free and spent the next fourteen years climbing the corporate ladder at a trading company. Seeking redemption, he set out to find his estranged father, but fears his employment would be jeopardized if he did so openly.
Sherlock, ever the taskmaster, instructs Amelia to gather her belongings and assume the role of chaperone to the Ambassador's daughter. On her way upstairs, she crosses paths with Detective Swann, who encourages her to give the new telephone a whirl and hands her his phone number for safekeeping.
Elsewhere, Sherlock lays down the law with Michael, ordering him to steer clear of Amelia and informing him that his father yearns for a reunion. However, Michael exits the conversation with a somewhat bitter taste in his mouth, leaving the room on a tense note.
Amelia, toting her suitcase, expresses her dismay to Sherlock, viewing her impending assignment at the ambassador's residence as a punishment. Sherlock assures her otherwise, revealing that her presence within the household is crucial to uncovering information about the keys the Red Thread acquired in exchange for Clara. He bestows his latest phone number upon her and urges extreme caution.
Amelia dives into her new role, witnessing a riveting session where Lady Violet schools Clara and a cohort of young ladies on proper feminine etiquette. Tragedy strikes at the session's close when Emma, one of the girls, plummets from a ladder and meets her untimely demise.
Meanwhile, Sherlock engages in an intelligence-sharing session with insurance investigator Birtwistle. He reveals the enigmatic tale of the Red Thread, while Birtwistle reciprocates by presenting him with five sets of footprints discovered in proximity to the coffin factory, accompanied by a button from a waistcoat. Sherlock astutely deduces that the button belongs to Dr. Watson and was deliberately planted as proof of his life. Subsequently, he tasks Birtwistle with verifying Amelia's claimed lineage as Lucia's daughter.
At the ambassador's residence, Amelia eavesdrops on a telephonic conversation between the ambassador and an unseen party. The ambassador subtly hints at sabotaging the ladder, causing the girl's fatal fall, and casually mentions receiving payment for his missing jewels. Desperate to alert Sherlock, Amelia attempts to call him, only to find his phone inoperative. Sherlock, equally frustrated, grapples with Detective Swann's assistant to fix the phone. In parallel, he discovers a series of common phone numbers that had contacted both Withersea and Inspector Whitlock. Once his communication device is functioning, he promptly dials these numbers to uncover their identities.
Back at the ambassador's mansion, Lady Violet assembles a group of gentlemen for the girls to practice dancing, amongst them Michael Wylie. Michael approaches Amelia, expressing contrition for his role in her predicament. Meanwhile, Sherlock phones the ambassador's house, where Violet answers and cordially invites him to the Italian ambassador's daughter's ball hosted at her estate. Concurrently, Amelia stumbles upon a knife, an exact replica of the one that terminated her mother's life.
The day of the ball dawns, and Sherlock prepares to depart. Birtwistle arrives with a revelation: Lucia did indeed have a daughter, conceived six months after her departure from London, contradicting Violet's earlier statement to Sherlock.
At the ball, Clara ventures inside while Amelia is relegated to waiting outdoors. Sherlock's arrival prompts him to usher her aside. Amelia confides in him about the knife she found in Lady Violet's parlor. Sherlock then expresses contrition for his apparent remoteness when he dispatched her to the ambassador's house.
As Sherlock steps inside, Amelia unexpectedly finds herself confronted by two assailants. Emerging just in time, Michael and Sherlock witness the carriage, with Amelia inside, rapidly departing the scene. Michael swiftly discharges his firearm, striking the driver, and together they rescue Amelia from imminent peril. Inside the carriage, Sherlock discovers yet another one of Watson's buttons, marking a cliffhanger conclusion to Sherlock & Daughter Episode 5.
