SHERLOCK 4x2 "The Lying Detective" Reaction & Discussion! | Benedict Cumberbatch | Martin Freeman

Sherlock appears to be heavily addicted to drugs, experiencing vivid hallucinations of Mary Watson. This is later revealed to be a deliberate act to make him seem unreliable and to provoke Culverton Smith into confessing, knowing Smith would dismiss a 'drug-addled' detective's accusations.

Sherlock's erratic behavior, his conversations with the hallucinated Mary, and his later confession that he was 'off his tits for weeks' but obtained the confession.

Culverton Smith, a wealthy and influential figure, confesses his murders to people and then administers a memory inhibitor (TD12) to make them forget, allowing him to operate with impunity. He even uses it on his own daughter, Faith.

Smith's 'board meetings' where he confesses to high-ranking individuals, the mention of TD12 as a memory inhibitor, and Faith's inability to recall the name of the person her father wanted to kill.

Mrs. Hudson, typically portrayed as a sweet landlady, demonstrates surprising skills and a hidden past. She drives an Aston Martin at high speeds, outmaneuvers police, and even handcuffs Watson, revealing her past as the widow of a drug dealer who owns property in central London.

Her high-speed driving, her ability to get Sherlock into the car boot, and her direct statement: 'I'm the widow of a drug dealer. I own property in central London. And for the last bloody time, John, I'm not your housekeeper.'

The entire elaborate plot, including the manipulation of Sherlock and Watson, the various 'characters' they encounter (Faith, the bus woman, the therapist), and the setup to expose Smith, was orchestrated by Eurus Holmes, Sherlock and Mycroft's secret sister. She possesses an intellect that rivals or surpasses theirs and has been imprisoned.

The revelation that the therapist is the same actress who played Faith and the woman on the bus, Mycroft's slip about 'the last time' with another brother, and Eurus's final reveal and explanation of her manipulations.