Guest Stars Lena Headey as Guinevere Daniel Brocklebank as Young Merlin Sebastian Roché as Gawain John McEnery as Lord Ardente Jason Done as Mordred Keith Baxter as Sir Hector Peter Benson as 1st Architect Roger Ashton-Griffiths as Sir Boris Peter Woodthorpe as Soothsayer Vernon Dobtcheff as 1st Physician Billie Whitelaw as Ambrosia Talula Sheppard as Lady Friend Janine Eser as Lady Elaine John Turner as Lord Lot Rachel Colover as Lady Igraine Justin Girdler as Young Galahad Emma Lewis as Elissa Alice Hamilton as Young Morgan le Fay Agnieszka Kozon as Young Nimue Nicholas Clay as Lord Leo Jeremy Sheffield as Lancelot Robert Addie as Sir Gilbert Paul Curran as Arthur John Tordoff as New Architect Timothy Bateson as Father Abbot Mark Jax as Uther Pendragon Peter Bayliss as 2nd Physician Nickolas Grace as Sir Egbert Thomas Lockyer as Cornwall Peter Eyre as Chief Physician