The new nemesis for the third series of Sherlock has been revealed as Charles Augustus Magnussen and played by Lars Mikkelsen.
The announcement came via a tweet from the show's co-executive producer Sue Vertue.
The Danish actor is probably best-known to TV viewers for his role as Troels Hartmann in the Nordic noir drama The Killing. He also had a starring role in Borgen.
The announcement was made yesterday as principal photography began on Series 3's third and final episode, entitled His Last Vow, which has been written by Vertue's husband Steven Moffat and is being directed by Nick Hurran. The title is a riff on the Conan Doyle short story His Last Bow, but it is believed that the character of Magnussen is based on the blackmailer Charles Augustus Milverton, who targets wealthy nobles in the Conan Doyle story The Adventure of Charles Augustus Milverton.
Episode one is called The Empty Hearse, written by Mark Gatiss and directed by Jeremy Lovering, and the second episode is entitled The Sign of Three, penned by Steve Thompson and helmed by Colm McCarthy. The first two episodes were filmed before the summer, with a production break then being taken to allow for other filming commitments.
It is unknown as yet when the new series - which stars Benedict Cumberbatch as Sherlock Holmes and Martin Freeman as Dr John Watson and is made by Hartswood Films for BBC One - will air.