Series 4 Episode 9 airs at 8.15pm on Saturday 26th November on BBC One and sees Gwen fight temptation before she commits an unspeakable act of betrayal when Sir Lancelot (Santiago Cabrera) returns from the dead.
With heads and hearts thrown into turmoil, Merlin becomes suspicious. Can a man really defy death, or is there something more sinister at play?
With Morgana at the head of a vast Southron army, a deadly net is closing in around Camelot, as the drama continues.
When the sorceress strikes, the ferocity of her attack forces everyone to run for their lives – even Arthur. But Morgana won’t let him escape that easily. And so begins a chilling hunt.
Can Merlin save the King from Morgana’s clutches? Or has Arthur’s luck finally run out?
Colin Morgan plays Merlin with Bradley James as Arthur, Katie McGrath as Morgana, Nathaniel Parker as Agravaine, Richard Wilson as Gaius, Angel Coulby as Gwen, Tom Hopper as Sir Percival, Eoin Macken as Sir Gwaine, Adetomiwa Edun as Sir Elyan and Rupert Young as Sir Leon.
The guest cast for this episode are Terence Maynard, who plays Helios, Ben Daniels, who plays Tristan and Miranda Raison, who plays Isolde.
Morgana and Helios have successfully captured Camelot, and Merlin and Arthur are outlaws on the run, in the last episode in this series of Merlin.
Trapped in Ealdor with a ruthless army closing in, their situation becomes desperate. Arthur must take control before Camelot is lost forever…
But faced with Agravaine’s betrayal and the strength of Morgana’s force, the young King has lost his conviction.
Only Merlin can restore his faith, and only an extraordinary act can prove to the King that he was born to rule.
Will the young warlock convince Arthur before his dreams of Albion fall to pieces?
Colin Morgan plays Merlin with Bradley James as Arthur. Katie McGrath as Morgana, Nathaniel Parker as Agravaine, Richard Wilson as Gaius, Angel Coulby as Gwen, Tom Hopper as Sir Percival, Eoin Macken as Sir Gwaine, Adetomiwa Edun as Sir Elyan, Rupert Young as Sir Leon.
The guest cast includes Terence Maynard as Helios, Ben Daniels as Tristan and Miranda Raison as Isolde.
BBC One's hit fantasy drama Merlin continues on Saturday nights, and this morning Digital Spy sat down with the show's co-creators Johnny Capps and Julian Murphy to answer your fan questions, submitted via Twitter or through our forums.
Q: Is there any more info on the Merlin movie?
A: it's in early stages - we're discussing talent right now, e.g writers, directors
Q: Will we ever see Merlin's mother again?
A: There's every chance! Wait and see!
Q: If you could have any actor star in Merlin, who would it be?
A: Tom Hollander, Brian Blessed, Felicity Kendal. In terms of guest casting, it depends on the parts - there's lots of names in our heads! Judi Dench, Ian McKellen...
Q: Will we see Morgause again?
A: Who knows?? There's no such thing as real death in Merlin.
Q: Will there be a sixth series of Merlin?
A: We've always planned five series, but it depends on how popular the show is . There's every possibility it could continue...
Q: Will Merlin reunite with Freya?
A: She's important to the legend, so there's a good chance they will reunite, yes!
Q: Will Uther return?
A: We loved working with Tony Head, we've got plenty of ideas as to how Uther could return! But when, we're not sure...
Q: Will we see either Arthur or Gwen confront Morgana this series?
A: Yes, there's a very exciting confrontation coming up between Gwen and Morgana!
Q: Any hope for a Merlin musical episode?
A: No plans for a musical, though Angel Coulby (Gwen) does have a beautiful singing voice!
Q: Will there be more scenes between Gwen & Elyan?
A: There's a big Elyan story coming up - their sibling relationship is tested, but it's not quite how you might imagine it.
Q: Will we get a glimpse of redemption for Morgana?
A: The end of this series is very surprising for Morgana! Stay tuned...
Q: Do you feel that Merlin has become a stronger show each series?
A: Yes - fantasy shows often grow with confidence. The closer we get to the legend, the richer and more interesting it gets... The ambition each year is to keep pushing the envelope. We're always working to make the show better!