The Darkest Hour

 The Darkest Hour is a two-part story consisting of the first and second epsidoes of the fourth series of Merlin. It is set a year after the occurences in The Coming of Arthur. Colin Morgan has said it focuses on darkness and that Morgana will release monsters that only come out in the dark from the underworld.

Synopsis
Part One

Merlin faces his toughest challenge yet when Morgana's blinkered determination threatens not only Arthur's future, but also the very balance of the world. With her magic stronger than ever, the sorceress summons the mighty Callieach to tear open the veil between the worlds.

Hellish creatures pour forth, killing all who succumb to their touch. With Uther a shadow of his former self, it falls to Arthur and his loyal knights, including Lancelot, to protect the kingdom, but it will take more than just swords to vanquish their enemy and Merlin is shocked to the core when he discovers the only way to restore the equilibrium requires a sacrifice of unimaginable proportions.

Part Two

The kingdom is on the brink of collapse and Morgana poised to strike. As Lancelot races back to Camelot with the dying Merlin, Arthur must continue on his mission to vanquish the Dorocha without them. Though the Knights know their journey to the Isle of the Blessed is fraught with danger, none could anticipate the sacrifice Arthur intends to make there.

Friendship and loyalty are tested to the limit, but in the end, it's the power of love that changes all their lives for ever.

Plot
The episode starts in a barran land in-between to cliffs. Morgana is wheeling a cart. Sir Leon, Sir Elyan and various other knights ride up to her and ask where she is heading. She says the sea of Medor.She turns and Leon recognizing her says "Lady Morgana"Morgana then throws the knights backwardsknocking them unconcious before returning to the cart were Morgause is, Morgana asks if she is allright, Morgause says yes but they still have a long way to go.In Camlot the servants are preparing for a celebration,Merlin goes to the kitchen to get Arthurs shirt and helps Pearcivle and gawaine steal food. Merlin takes Arthurs shirt to Arthurs chamber to find him already drest. Meanwhile Morgana and Morgause bord a boat that takes them to the isle of the blest. At camalot Gwen is looking after Uther who has become a broken man due to Morgana's betrayal.she tells Gaius that she looks after Uther for Arthurs sake.

Cast

 * Colin Morgan as Merlin/Emrys
 * Bradley James as Arthur Pendragon
 * Katie McGrath as Morgana Pendragon
 * Emilia Fox as Morgause
 * Gemma Jones as The Cailleach
 * Angel Coulby as Guinevere
 * Anthony Head as Uther Pendragon
 * Richard Wilson as Gaius
 * John Hurt as the voice of Kilgharrah
 * Rupert Young as Sir Leon
 * Santiago Cabrera as Sir Lancelot
 * Tom Hopper as Sir Percival
 * Adetomiwa Edun as Sir Elyan
 * Eoin Macken as Sir Gwaine
 * Nathaniel Parker as Agravaine
 * Michael Cronin as Geoffrey of Monmouth
 * Katie Moore as Drea
 * Zee Asha as Audrey
 * James Greene as Ferryman
 * Sarah Beck Mather as Vilia
 * Charlie Petryszyn as rescued child
 * William Rowlands as rescued child
 * Anya Davies as rescued child

Broadcast
Part One October 1 2011 - 7.50pm BBC One and BBC One HD

Part Two October 8 2011 - 8.05pm BBC One and BBC One HD

Previews
First preview clip

More preview clips

Trivia

 * The Darkest Hour (Part One) is the first episode of Merlin to air on the same night as an episode of fellow BBC Saturday night drama, Doctor Who. As the finale of Doctor Who Series 6, The Wedding of River Song, is to be broadcast right before the first episode of Series 4.