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.

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.

The British Prime Minister himself calls at Baker Street to seek Holmes's help with a political crisis. A highly confidential letter from a foreign power has been stolen from the Secretary of State for European Affairs, threatening the world with war. Minutes after the Prime Minister's departure, Holmes receives another visit, from a veiled lady.In his investigation, a bloodstain is clearly an important clue, but whose is the blood? Holmes sees through the deceptions of great and small alike.

Holmes and Watson are staying with Reginald Musgrave, the head of an ancient Sussex family, when his butler, Brunton, suddenly disappears. Brunton (something of a ladykiller and a highly educated man) had been taking an interest in an ancient family tradition called 'the Musgrave Ritual', which centres on a Carolingian riddle. And then a second member of the household vanishes, equally suddenly. The old riddle proves to be the key to tracing the butler's body and finding the treasure the dead man was after - the crown jewels lost in the English Civil War. And as so often, it's a case of 'cherchez la femme'.

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...

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.

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.