Mary Morstan

Mary Morstan, John's wife, is a pretty little liar.

That, Sherlock can see it at first glance. But beside some details about her, he can hardly learn anything. For once, trusting John's choice, Sherlock will be friendly with Mary, who appreciates him too. Mary's noticeable talent is to make the autistic genius behave quite normally!

Sherlock doesn't show any sign of "jealousy" towards her -Major Sholto will be less lucky. And Mary support John's need for action, his strange adventures with his friend. Patient, always taking things good humouredly, she gives John's life the joy and sunshine that was missing before.

Actually, after having helped him to overtake Sherlock's first death, she will provide her husband's life with much more than that. John Watson is definitely not a quiet and normal citizen.

Charles Augustus Magnussen

Magnussen is a powerful man. Several ways lead to power. His favourite one: information. Blackmail, intimidation, pressure points... Most people don't assume their weaknesses, and Magnussen manipulates them like a maestro.

Casting 3.3 His last vow

Lady Elisabeth Smallwood : Lindsay Duncan - IMDB page

As an MP, Lady Smallwood leads a commission of inquiry about a possible influence of Charles Augustus Magnussen, a powerful media mogul, and the British government. Magnussen has visited 10 Downing Street seven times over the year, but refuses to give any explanation. Magnussen and Lady Smallwood are both cold-blooded, but Magnussen is unscrupulous and blackmails his opponent. Lady Smallwood will need the help of the only person who doesn't fear Magnussen: Sherlock.

Charles Augustus Magnussen : Lars Mikkelsen - IMDB page

Magnussen is as powerful in GB as Mycroft himself -aka he is the most powerful man, ex-aequo. Why did he choose to operate in/from Great-Britain? Because British "are a people of ruminants". Proud and contemptuous, Magnussen is a freaky villain, however, he has no blood on his hands (not directly!). He threats, hurts, gives, leads to suicide, but doesn't kill himself. But he will provoke Sherlock's hate though, after having succeeded in trapping the genius.

Casting 3.2 The sign of the three

Major James Sholto : Alistair Petrie - IMDB page

An ancient officer highly estimated by Watson, Major Sholto gained a lot of enemies. After a failed mission, several young soldiers died, and their families take Sholto for responsible. That's why Sholto lives now retired from active duty and life. But he makes an exception for John's wedding, and faces an unexpected hostility: Sherlock's jealousy!

3.3 His last vow

In his best man's speech, Sherlock made a last vow: protect John & Mary. Charles Augustus Magnussen, a media mogul and a powerful man, understands very well the interest of this lever on Mycroft's brother.

Magnussen decides to blackmail an MP, and then provokes Sherlock. He chooses to provoke also Mary, who will show her true face.

3.2 The sign of the three

Sherlock is terrified: John asked him to be his best man for his marriage. Sherlock has a speech to make. A real speech in front of real people.

He will do it in his so particular way, avoiding a murder at the same time.

Casting 3.1 - The empty hearse

Mary Morstan : Amanda Abbington - IMDB page

John's fiancée. Despite the special mood of the reunion between both friends, she likes Sherlock straightaway. She doesn't fear his look upon her. Neutral when John refuses, at first, to forgive, she will then support their reconciliation.

3.1 The empty hearse

In London, truth has finally been revealed : two years after Sherlock's death, all suspicions of fraud against him have been cleared, and Moriarty's plot is now clear.

During this two year, Sherlock has dismantled Moriarty's web. He finished his work, but has been captured by Serbian secret services. Exfiltrated by Mycroft, he's got a new mission : find out an underground terrorist cell.

But first, he will have to face another adversary : John...