EDITORIAL USE ONLY / NO MERCHANDISING / BOOK PUBLISHING TO BE CLEARED BEFORE USE Mandatory Credit: Photo by Hartswood Films/REX/Shutterstock (4273017c) Martin Freeman and Benedict Cumberbatch 'Sherlock' TV Programme. - 2014
(Picture: Hartswood Films/REX/Shutterstock)

Filming on Sherlock series four is officially underway.

Co-creator Mark Gatiss previously teased that shooting had started with a familiar skull picture, but this newest announcement from the BBC has given us a hint of what to expect.

The tagline for the new series reads: ‘We all have a past. Ghosts. They are the shadows that define our every sunny day…’

It sounds lofty enough to possibly be a line of dialogue – maybe one uttered by Sherlock himself – but we’ll have to wait and see.

The show is back for three more feature-length episodes with Benedict Cumberbatch and Martin Freeman reprising their roles as Sherlock and John Watson.

Sherlock likes the dark shirt/dark suit combination (Picture: BBC)
The boys are back in town…hopefully in the modern day this time (Picture: BBC)

Cumberbatch said he was ‘genuinely thrilled to be back filming Sherlock with all the cast and crew. I can’t wait for everyone to see season four. But you will have to wait…though not for long…And it will be worth it.’

Not a long wait, eh Benedict? Could we be looking at a summer series like season one?

Co-creators, writers and executive producers Steven Moffat and Mark Gatiss added: ‘Sherlock series four – here we go again! Whatever else we do, wherever we all go, all roads lead back to Baker Street – and it always feels like coming home.

Benedict Cumberbatch in Sherlock
Cumberbatch has promised that series four will be worth the wait (Picture: BBC)

‘Ghosts of the past are rising in the lives of Sherlock Holmes and John Watson bringing adventure, romance and terror in their wake. This is the story we’ve been telling from the beginning. A story about to reach its climax…’

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