With filming underway on the third season of Sherlock, the BBC has added British TV veteran Amanda Abbington to the cast. The role has yet to be identified, but she will “significantly impact” the lives of Martin Freeman‘s John Watson and Benedict Cumberbatch’s Sherlock Holmes and could appear in more than one of the three feature-length episodes, Deadline said.

(Abbington is also Freeman’s longtime real-life partner, and showrunner Steven Moffat last year said that one of the key words for this season would be “wedding”…) Abbington also stars in ITV’s Jeremy Piven period series Mr. Selfridge which makes its Stateside debut on PBS.

In related news, Sherlock co-creator and co-star Mark Gatiss recently revealed that the title of the first Season 3 episode will be The Empty Hearse, which is believed to be based on Arthur Conan Doyle’s The Adventure Of The Empty House, one of 13 stories in the Return Of Sherlock Holmes cycle.

Holmes was last seen stepping off the side of a building in Season 2 finale, The Reichenbach Fall. Sherlock last aired in the UK in January 2012 and in the U.S. on PBS last May. The new trilogy is expected this winter.