Sherlock: 'The darkest season yet'
Media playback is unsupported on your device

Sherlock: New series 'the darkest season yet'

Benedict Cumberbatch, Martin Freeman and Amanda Abbington talk about season four of Sherlock, which writers have described as the darkest yet.

The new series of Sherlock starts on BBC One on New Year's Day at 20:30 GMT.

  • 24 Dec 2016
Go to next video: Putting the meat-free burger to the test