The Beekeeper's Apprentice

Back in Oxford, Russell hides the cipher photographs in the Bodleian Library but makes no progress decoding the Roman numerals despite intensive study. 

That night, Russell suffers a vivid nightmare featuring books about Henry VIII. Upon waking, the image of Henry VIII provides the crucial insight: The Roman numeral VIII suggests the code uses base eight rather than the standard base ten. She applies this base-eight key and successfully deciphers the message, which spells out MORIARTY. This revelation leads her to realize that Patricia Donleavy, her former mathematics tutor who had taught her base-eight number theory and introduced her to Moriarty’s mathematical work, must be their adversary. She also belatedly realizes that she has been working so hard that several people have passed near her table and could’ve seen what she’s working on.

When Russell leaves the library, she notices her watchers have mysteriously vanished. Alarmed, she rushes to telephone Holmes through Mr. Thomas but discovers that telephone lines to his area are down. Returning to her room, she finds a greasy smudge on the doorknob. Inside, she discovers Holmes waiting for her, disguised as an elderly priest.

Holmes reveals he had been watching Russell in the library and witnessed her breakthrough with the cipher. They exchange critical updates: Russell has identified Donleavy as their enemy, while Holmes confirms that the sudden disappearance of his own watchers alerted him to the immediate danger and prompted his journey to Oxford.

Holmes explains that his apparent illness was an elaborate ruse orchestrated with help from Mycroft. He immediately calls Mycroft to request backup support for their final confrontation. Russell quickly changes into men’s clothing and arms herself with weapons.

They flee Oxford in Russell’s motorcar, taking back roads through the countryside at high speed to avoid detection. Upon reaching Russell’s farm, they hide the car in Patrick’s barn and request his secrecy about their presence. Under cover of darkness, they walk across the downs, carefully avoiding the guards stationed around Holmes’s property, and covertly enter his cottage through a secret passage. Inside the laboratory, they are immediately ambushed by Patricia Donleavy, who waits with a pistol drawn.

Donleavy holds both Holmes and Russell at gunpoint in the laboratory. Holmes reveals that he knows her true identity as Professor Moriarty’s daughter, bringing their long-hidden conflict into the open. Donleavy confirms her parentage and reveals she is dying of cancer, which has accelerated her timeline for revenge against Holmes for her father’s death at Reichenbach Falls.

She details her lifelong obsession with Holmes and the elaborate manipulations she has orchestrated, including her role as Russell’s mathematics tutor. Donleavy presents a typed suicide letter that would destroy Holmes’s reputation and threatens to kill Russell if he refuses to sign it. Donleavy shoots Russell in the arm to convince Holmes of her seriousness. Holmes appears to comply, moving toward the document as if to sign.

However, as Holmes prepares to put pen to paper, he instead delivers a scathing speech denouncing both Donleavy and her father’s legacy. Enraged by his defiance, Donleavy raises her gun to shoot Holmes. Russell hurls a heavy ink bottle, striking Donleavy’s hand just as the weapon fires. Russell then tackles Donleavy, and during their struggle for control of the gun, it discharges again. The bullet passes through Russell’s shoulder and collarbone before striking and killing Donleavy. Russell collapses and loses consciousness.

Russell awakens in a hospital after several days of feverish delirium. Holmes and her doctor explain that while she has suffered a broken collarbone and severe trauma, she will make a full physical recovery. She receives visits from Watson and Mycroft but refuses to see her aunt, instead arranging to convalesce at Holmes’s cottage under his care.

While Russell’s body heals, she remains emotionally numb and withdrawn. She grows increasingly irritable with Holmes’s presence, reacting with anger when he brings out a chess set. Holmes recognizes her psychological state and gives her a letter from Jessica Simpson, the child she had rescued in Wales. The letter praises Russell’s strength and courage, triggering an emotional release as Russell finally weeps.

After this breakthrough begins her emotional recovery, Holmes invites Russell to join him on a restorative trip to France and Italy. When he again suggests a game of chess, Russell agrees but insists they play as complete equals rather than mentor and student, marking the renewal of their partnership.