Contains spoilers for this episode and earlier episodes.
John tells his therapist that Sherlock is dead, before the story returns to the months leading up to his loss. Sherlock has become a reluctant celebrity through his successful cases. Moriarty stages simultaneous security breaches at the Tower of London, the Bank of England and Pentonville Prison, then allows himself to be caught. His trial seems straightforward until threats against the jurors' families secure an acquittal.
Moriarty turns public admiration into suspicion. A kidnapped child recoils from Sherlock after being rescued, encouraging police doubts about how he solves crimes so quickly. Journalist Kitty Riley prepares an exposé with a supposed actor called Richard Brook, whom Sherlock recognises as Moriarty. Brook claims Sherlock hired him to invent a criminal enemy. As the accusations close in, Sherlock asks Molly for help and arranges a meeting on the hospital roof.
Moriarty reveals that his miraculous computer code never existed; bribery achieved the break-ins. He says gunmen will kill John, Mrs Hudson and Lestrade unless Sherlock jumps. When Sherlock suggests he can force a way out, Moriarty shoots himself, removing that option. Sherlock telephones John, claims to have fabricated his career and falls from the roof as John watches. John later visits the grave and refuses to accept that his friend was a fraud. Nearby, unseen by John, Sherlock stands alive, with no explanation of how he survived.