The Final Problem (Sherlock)
Panic stricken, she picks up a mobile phone and attempts to call for help only to hear the voice of Jim Moriarty announce, "Welcome to the final problem".
Meanwhile, Sherlock talks to Eurus, but after toying with him, particularly about Redbeard's death, she attacks him and knocks him unconscious (by pretending that there was a glass wall between them).
It’s revealed that five years prior, Mycroft granted Eurus an unsupervised five-minute interview with Moriarty as a Christmas present in exchange for detecting national security threats to Britain.
John wakes up in Eurus’ cell with Sherlock, Mycroft, and the governor and the young girl's distress call comes through the speakers.
Although Eurus forces Sherlock onward with the prospect of saving the girl on the aeroplane, he eventually stops the games by threatening to shoot himself when she orders him to murder either John or Mycroft.
Mycroft explains to his and Sherlock's parents, who are angry that they had been told that Eurus was dead, that she refuses to speak to people anymore.
[4] The character Victor Trevor is a reference to "The Adventure of the Gloria Scott" (1893), where he appears as Holmes' first ever close friend, albeit in university rather than in childhood.
[6] In the final sequence, "The Adventure of the Dancing Men" (1903) is referenced with the following cipher seen on a chalkboard,[4] which reads "AM HERE ABE SLANEY": This idea (pictorial coded messages) was previously used as inspiration for the earlier series 1 episode The Blind Banker.
[7] Musician Paul Weller made a cameo appearance, in a non-speaking role as a man lying on the floor in a Viking costume, seen near the end of the episode.
Among the more positive reviews was Sean O'Grady of The Independent who gave the episode four out of five stars, stating that "Benedict Cumberbatch and Tim Freeman [sic] are their usual accomplished double act" although suggesting "Maybe Sherlock needs a little more reimagining".
[15] Meanwhile, Michael Hogan of The Daily Telegraph gave the episode five out of five stars, praising that "the dazzling script delivered laughs, excitement, and emotion .. we were left with a wiser Holmes and Watson."
"[17] Neela Debnath of the Daily Express was also positive, writing "I can't fault the thrill ride that The Final Problem takes viewers on from the beginning to the end.
"[18] Two separate reviews in The Observer and The Guardian were positive, with one describing it as too byzantine, but "much better than it looked"[19] and the other writing "with a visual swagger far beyond the budget – and including an eerily beautiful high-security violin duet for Sherlock and Eurus – this was a fine way to go.
She noted that Eurus, a stereotypical female villain, "ticks every box for the kind of madwoman who gets locked up in an asylum in a 19th century melodrama" and commits crimes only motivated "by a desire for male attention.
