As filming gets underway on the third season of Steven Moffat and Mark Gatiss’ modern detective series Sherlock, more details are beginning to emerge regarding what we can expect to see from the series in the future. The title of the first episode – “The Empty Hearse” – was revealed by Gatiss on the first day of filming, and the casting of actor Tomi May in the episode has triggered speculation that James Moriarty’s right-hand man, Sebastian Moran, may make an appearance as the new antagonist.

There’s more speculation ahead; Deadline is reporting that Amanda Abbington has been cast in an important, though currently unnamed role this season. Abbington is currently starring alongside Jeremy Piven in British period drama series Mr Selfridge, and also appeared in Craig Viveiros’ 2011 prison movie Ghosted.

From everything we’ve learnt so far, it’s looking extremely likely that Abbington will play John Watson’s wife, Mary Morstan. The teaser word for the second episode of the season is “wedding”, and the article quotes their Sherlock source as saying that she will have a “significant impact” on John and Sherlock’s lives, and also that Abbington “could appear in more than one of the three feature-length episodes.” Then, of course, there’s the fact that Abbington and Martin Freeman are longtime partners in real life.

On the other hand, that explanation for Abbington’s casting seems almost too perfect. It’s long been assumed that Mary Morstan would appear in the third season, since in Arthur Conan Doyle’s stories the detective duo meet her quite early on in a case, and John marries her shortly afterwards. But Abbington could just easily be playing a different female character from the stories, or even an original role created for the series. When questioned on the subject of the teaser words last summer, Gatiss warned that they, “...May be misleading, are not titles, are only teases or possibly clues, but might be deliberately designed to get you into a lather.”

No doubt fans of the show are already in a lather over this latest casting news. In Doyle’s stories, John’s marriage to Mary leads to him moving out of 221B Baker Street, and in Guy Ritchie’s recent Sherlock Holmes movies their relationship drives a significant wedge into the Holmes-Watson bromance (though this is temporarily alleviated when Sherlock throws Mary off a moving train). With at least one more season planned after this one, however, it doesn’t look like Watson will be leaving his detective days behind him any time soon.

Are you convinced that Abbington will be playing Mary Morstan, or do you suspect that Mark Gatiss and Steven Moffat are deliberately bluffing their audience? Tell us your theories in the comments.

Sherlock Season 3 will being airing this winter.

Source: Deadline