BBC One’s Twitter feed announced earlier today: “Amanda Abbington joins the third series of #Sherlock in a role that significantly impacts upon the lives of John and Sherlock.”

Abbington is the longtime partner of Sherlock star Martin Freeman, who plays John Watson. The actress has previously appeared in Man Stroke Woman, Casualty, Dream Team and Steven Moffat’s Coupling.

Written by Mark Gatiss and directed by Jeremy Lovering, ‘The Empty Hearse’ began filming last week.

> Find out all the details on Series 3 so far in our summary.

Who do you think Amanda Abbington’s character will be? Let us know below…

> Buy the Series 1-2 boxset on Amazon.

> Buy the BBC’s official book, Sherlock: The Casebook, on Amazon.

Watch a clip from The Hounds of Baskerville…