Sir Lancelot makes a shocking return from the dead and old feelings reignite, making Gwen fight temptation to avoid committing an unspeakable act of betrayal that would destroy the legacy of Camelot forever. With heads and hearts at stake Merlin soon becomes suspicious. Can a man of honour break oaths and defy death or is there something more than meets eye?
Arthur tells Agravaine that he wishes to marry Guinevere despite everyone's opinion. This worries his uncle and therefore he goes to see Morgana. He startles her and she puts a dagger to his chest, she withdraws it when she sees who it is. Agravaine tells her about the King's plan to marry and Morgana starts to worry and become angry, "I will not see that woman upon my throne!" she says.
thumb|300px|rightMorgana sets off in search for the Dochraid who tells her how to use a coin that can raise a Shade, a shadow of a dead person. She raises a Shade of Lancelot in the Pool of Nemhain and he goes to Camelot to try and win back the heart of Gwen (who by then has accepted Arthur's proposal). Lancelot returns to Camelot and everyone is overjoyed by his return but Merlin grows suspicious about his return. Gwen stays loyal to her future husband, so Morgana gives Agravaine an enchanted bracelet that will make Gwen love Lancelot once again. Agravaine gives Lancelot the bracelet who then gives it to Gwen as a "wedding gift" for their marriage, wishing her a happy life with Arthur.Merlin discovers Lancelot's shade nature and, believing that Morgana resurrected him and that Lancelot may harm Arthur, is prepared to use magic to stop him when he participates in a tournament. However, during the tournament, Lancelot, although he initially wounds Arthur, yields his weapon, refusing to harm Arthur. Merlin is relieved that Arthur is alive but when he spots Gwen going to visit Lancelot, his suspicions increase. Lancelot manages to get Gwen in the Council Chambers in the dead of night. Merlin tries to stop Lancelot with his magic but since Lancelot is a shade, he is unharmed and he knocks Merlin unconscious. Agravaine summons Arthur to the council chambers and they, along with the recovered Merlin, catch Lancelot and Gwen kissing. Enraged by this, Arthur attacks Lancelot and they engage in a fierce battle. Lancelot attempts to kill Arthur but Merlin disarms Lancelot with his magic, giving Arthur a chance to kill him, however Gwen gets between the two and Arthur immediately stops. Lancelot and Gwen are thrown in separate cells and Gwen pulls off the bracelet and throws it away, freeing herself from the enchantment. Gwen is later brought to the Council Chambers and Arthur angrily asks her what she was doing with Lancelot and why she would betray him in such a manner. Gwen apologises for her actions, telling Arthur that she has always loved him but somehow got drawn towards Lancelot after his return without knowing what she was doing. Arthur has Gwen banished from Camelot, unable to have her executed for her betrayal. Merlin tells Gaius that Morgana always wanted to get rid of Gwen and that they should tell Arthur that Lancelot is a shade but Gaius tells him that it will not clear Gwen's apparent betrayal. Agravaine later goes to Lancelot's cell and gives him an order for Morgana to make Lancelot kill himself. Merlin tells Arthur that Gwen is a good person even though she betrayed him but Arthur tells him that while he loves Gwen, he can never trust her, leaving Merlin frustrated. Agravaine then informs Arthur about Lancelot's death and Arthur, who still respects Lancelot as a man of honour, orders Lancelot's body to be buried. Merlin goes to a lake and puts Lancelot's body in a boat and then frees Lancelot's soul from Morgana's control, bringing him back to life for a moment. The true Knight sees Merlin and says feebly "Merlin, thank you."Merlin gives a weak smile and Lancelot dies peacefully. The boat on which he is laying is set off over the lake and towards the mountains. Merlin sets the boat alight using Magic and has a tearful farewell with his past friend.
- Sir Lancelot - Santiago Cabrera
- Merlin - Colin Morgan
- King Arthur- Bradley James
- Guinevere - Angel Coulby
- Gaius - Richard Wilson
- Morgana - Katie McGrath
- Agravaine - Nathaniel Parker
- Sir Leon - Rupert Young
- Sir Gwaine - Eoin Macken
- Sir Elyan - Adetomiwa Edun
- Sir Percival - Tom Hopper
- The Dochraid - Maureen Carr
26 November 2011 at 8.15pm on BBC One
- This episode, along with the finale, is Colin Morgan's favourite episode of Series 4. It is also one of producer Johnny Capps', favourite episode. The episode has also received a lot of praise from crew working on the episode, as well as critics, with website DigitalSpy stating that, "First of all, let's get this out of the way - 'Lancelot du Lac' is one of the best episodes Merlin has ever produced."
- According to Lancelot, he was saved by the Madhavi people who found him in one of the silk routes high in the Feorre Mountains in Cenred's Kingdom.
- With 6.01 million viewers, it became the most watched Merlin episode of Season 4, but then, The Sword in the Stone: Part One overtook it with a massive 7.13 million viewers.
- "Lancelot du Lac", translates to "Lancelot of the Lake", in English.
|The Darkest Hour • The Wicked Day • Aithusa • His Father's Son • A Servant of Two Masters • The Secret Sharer • Lamia • Lancelot du Lac • A Herald of the New Age • The Hunter's Heart • The Sword in the Stone|