Fantasy-drama based on Arthurian Legend - the darkest hour is just before the dawn.
Share this with
This programme is not currently available on BBC iPlayer
There are no upcoming broadcasts of this programme
Sat 27 Jul 2013 12:05
All previous episodes
See all from Series 4
See all clips from Series 4
Read more from the special effects director on the BBC TV blog.
See all galleries from Series 4