This episode was transmitted on Saturday September 19th, 2009 (UK)
The official details about the episode are as follows…
In the dark tunnels deep beneath Camelot, an ancient tomb is discovered, filled with treasure. Gaius begs the King to seal it shut again, fearing that the tomb belongs to Cornelius Sigan, an evil sorcerer who cursed Camelot and swore he would, one day, return to destroy the city. But Uther is too taken with the treasure to listen, insisting Sigan is just a fairy tale.
Meanwhile, new servant Cedric muscles in on Merlin’s position as Arthur’s right-hand man and turns the prince against his loyal friend. Merlin is convinced the slippery newcomer is up to something and he’s right – Cedric is a con man and a thief who is after the magnificent jewel found at the heart of the tomb. Little does Cedric know his precious prize is more dangerous than he could possibly imagine.
Camelot has never been more vulnerable but how can Merlin make things right when, thanks to Cedric, he might have lost Arthur’s friendship for good? Merlin faces the prospect of turning to the creature he swore he’d never trust again – The Great Dragon.
Richard Wilson is Gaius, Anthony Head is Uther, Bradley James is Arthur, Mackenzie Crook is Cedric, Colin Morgan is Merlin and John Hurt is the voice of The Great Dragon. The cast also includes Katie McGrath as Morgana and Angel Coulby as Gwen.