Violet Hunter consults Holmes about Edward Rucastle's offer of a job. He wants her to cut off her hair before coming to work for him as a governess. Holmes sees a sinister motive and investigates.

Holmes's brother, Mycroft, seeks his help in deciphering the story a man tells about being kidnapped and forced to translate for an injured Greek. Holmes investigates the disappearance of Paul Kratides, abducted by two villains, Latimer and Kemp, with the aim of forcing him to sign a document releasing his sister Sophie to marry Latimer.

A young solicitor, John Hector McFarlane, seeks Holmes's help after retired builder Jonas Oldacre dies in a fire. McFarlane, who benefits from Oldacre's will, is suspected of murder and asks Holmes to clear his name. Holmes looks for another motive and another killer, and dresses up as a tramp to get the information he needs about the Oldacre household. The surprising answer he finds is that Oldacre is not exactly dead.

Dr Trevelyan calls on Holmes on behalf of his friend Blessington, after a Russian father and son vanish during a consultation. Blessington knows of no one who wishes him ill, but he is found hanged the next day. Holmes investigates, with advice from Watson.

A notice in a newspaper seeks red-headed men, inviting them to join a league which will pay them well - and Jabez Wilson, a pawnbroker who responds, finds he is hired and paid generously for spending four hours a day copying an encyclopedia in long hand. When the league is suddenly dissolved, Holmes is asked to find out what has been going on, and he quickly suspects crime. Indeed, behind this curious arrangement lurks Holmes's arch-enemy, Professor Moriarty.

The French government sends for Holmes when the Mona Lisa is stolen from the Louvre. Holmes swiftly decides he is dealing with a mastermind - and none other than his old enemy Professor Moriarty himself.Holmes foils Moriarty's plans to sell Leonardo da Vinci's masterpiece and trails him to Switzerland, where they meet and fight to the death above the famous waterfall at Reichenbach.

Three years on from Holmes's fatal fall into the Reichenbach Falls, Watson wrestles with a murder case under his own steam. But who is the enigmatic stranger in the Coroner's court, listening intently to all the evidence? Holmes returns home and explains how he escaped death at Reichenbach, while Moriarty lost his life. Holmes and Watson must now bring a partner of Moriarty's to justice, by proving he is a murderer.

Holmes is called in to investigate a murder. Lady Brackenstall says she saw a gang of men kill her bullying husband, Sir Eustace, but on Holmes's arrival the case seems to have been solved. Holmes is uneasy and returns to the scene of the crime, where he finds things are not as they appear to be. And Watson is curious to hear about the lady's love affair with a sea captain during a long voyage.

Holmes is asked by the country's Prime Minister to aid in the recovery of a stolen diplomatic letter, which, if published, might lead England into war.

An obscure family document containing an enigmatic ritual holds the key to a hidden treasure if Holmes can decipher the mystery.

Neville St Clair works in the City of London and is a man of very regular and respectable habits. One day, his wife goes into town for lunch and is shocked to see her husband in the window of an opium den. That evening, he fails to return home, and Mrs St Clair decides to consult Holmes.

The Duke of Holdernesse needs Holmes's help when his son, Lord Arthur Saltire, is kidnapped from the Priory School. Holmes finds the connection between an old mystery and a teacher who has also gone missing.

Holmes is curious about a series of attacks on figures of the French Emperor Napoleon Bonaparte around London. One such incident leads to a violent death, and he investigates. Lestrade sees an Italian connection and proposes to focus Scotland Yard's attention on the Italian quarter of London, but Holmes is more interested in Chiswick.