<Li> Tom Hopper as Percival </Li> <Table> <Tr> <Td> </Td> </Tr> </Table> <Table> <Tr> <Th> No . overall </Th> <Th> No. in series </Th> <Th> Title </Th> <Th> Directed by </Th> <Th> Written by </Th> <Th> Original air date </Th> <Th> UK viewers (millions) </Th> </Tr> <Tr> <Th> 27 </Th> <Td> </Td> <Td> "The Tears of Uther Pendragon - Part 1" </Td> <Td> Jeremy Webb </Td> <Td> Julian Jones </Td> <Td> 11 September 2010 (2010 - 09 - 11) </Td> <Td> 6.49 </Td> </Tr> <Tr> <Td_colspan="7"> A year has passed with many fruitless quests in search of the missing Lady Morgana . The despondent Prince is all but ready to give up, but as he and Merlin recover from their latest skirmish a bruised, bloodied figure emerges from the mist; it is the Lady Morgana . King Uther is overjoyed, but then starts to lose his mind . Merlin thinks that magic is the cause; could this be the work of his dutiful ward? The young warlock puts himself in grave danger trying to find out whose side Morgana is really on . </Td> </Tr> <Tr> <Th> 28 </Th> <Td> </Td> <Td> "The Tears of Uther Pendragon - Part 2" </Td> <Td> Jeremy Webb </Td> <Td> Julian Jones </Td> <Td> 18 September 2010 (2010 - 09 - 18) </Td> <Td> 6.06 </Td> </Tr> <Tr> <Td_colspan="7"> With Merlin gravely ill from the Serket's poison, Morgana and Morgause continue with their evil plan . They have mentally incapacitated Uther and convinced his enemy, Cenred, to invade Camelot . The fate of the kingdom now rests on Arthur's shoulders . The Prince and his Knights resist the invaders, but Cenred's soldiers are not the only threat they face . Can Merlin stop Morgana in time to save Arthur from the enemy within? </Td> </Tr> <Tr> <Th> 29 </Th> <Td> </Td> <Td> "Goblin's Gold" </Td> <Td> Jeremy Webb </Td> <Td> Howard Overman </Td> <Td> 25 September 2010 (2010 - 09 - 25) </Td> <Td> 6.22 </Td> </Tr> <Tr> <Td_colspan="7"> After stumbling into a secret chamber, Merlin releases a mysterious goblin with a penchant for making trouble and a lust for gold . It takes control of Gaius and causes all sorts of mischief . Merlin is desperate to find a way to free Gaius . </Td> </Tr> <Tr> <Th> 30 </Th> <Td> </Td> <Td> "Gwaine" </Td> <Td> David Moore </Td> <Td> Julian Jones </Td> <Td> 2 October 2010 (2010 - 10 - 02) </Td> <Td> 6.42 </Td> </Tr> <Tr> <Td_colspan="7"> Merlin and Arthur find themselves outnumbered in a bar fight but an enigmatic young man helps them win . The man's name is Gwaine and he risks his own life to protect Arthur but during his act of bravery he is seriously wounded . The Prince decides to take him back to Camelot where he could make a recovery with Gaius' help . Meanwhile, two unscrupulous "knights" plot to murder the Prince . </Td> </Tr> <Tr> <Th> 31 </Th> <Td> </Td> <Td> "The Crystal Cave" </Td> <Td> Alice Troughton </Td> <Td> Julian Jones </Td> <Td> 9 October 2010 (2010 - 10 - 09) </Td> <Td> 6.36 </Td> </Tr> <Tr> <Td_colspan="7"> When Merlin enters the Crystal Cave, an old sorcerer shows Merlin a vision of the near future in which Morgana appears to kill Uther . Events begin unfolding as they did in the vision and Merlin misinterprets Morgana's nighttime visit to Morgause as sneaking off to kill Uther . Merlin tries to stop her, accidentally fracturing Morgana's skull . Merlin cannot live with Arthur and Uther's extreme anguish over Morgana's impending death and forces the Great Dragon to help save her . Unfortunately, a shocking revelation by Uther means that Morgana is more bitter than ever and Merlin now has to foil a real assassination attempt . </Td> </Tr> <Tr> <Th> 32 </Th> <Td> 6 </Td> <Td> "The Changeling" </Td> <Td> David Moore </Td> <Td> Lucy Watkins </Td> <Td> 16 October 2010 (2010 - 10 - 16) </Td> <Td> 6.40 </Td> </Tr> <Tr> <Td_colspan="7"> Uther has Arthur get engaged to Princess Elena, who arrives in Camelot . Elena is not dainty or lady - like and Arthur does not love her . Furthermore, her nanny, Grunhilda, is working for the Sidhe (pronounced "Shee") Elder to use Arthur's marriage to take over Camelot . As Merlin and Gaius battle Grunhilda to free Elena from the Sidhe, Arthur must decide if he will go through with the wedding . </Td> </Tr> <Tr> <Th> 33 </Th> <Td> 7 </Td> <Td> "The Castle of Fyrien" </Td> <Td> David Moore </Td> <Td> Jake Michie </Td> <Td> 23 October 2010 (2010 - 10 - 23) </Td> <Td> 6.82 </Td> </Tr> <Tr> <Td_colspan="7"> Gwen is kidnapped one night as part of a plot by Morgana, Morgause and Cenred . Cenred has Gwen's estranged brother Elyan captive at Castle Fyrien and, after a quick reunion, releases Gwen with a choice: bring Arthur to Cenred or Elyan will die . Arthur, Merlin and Gwen plan to save Elyan by using a secret entrance to Castle Fyrien, but things get complicated when Morgana decides to come with them . </Td> </Tr> <Tr> <Th> 34 </Th> <Td> 8 </Td> <Td> "The Eye of the Phoenix" </Td> <Td> Alice Troughton </Td> <Td> Julian Jones </Td> <Td> 30 October 2010 (2010 - 10 - 30) </Td> <Td> 6.92 </Td> </Tr> <Tr> <Td_colspan="7"> Arthur sets out on a quest to retrieve the Golden Trident from the Fisher King's Realm . But unbeknownst to Arthur, Morgana and Morgause have devised a clever plan to stop him from ever returning to Camelot . Once again, Merlin (this time with the help of Gwaine), must foil the plans of the ill - wishing sisters to save Arthur and discover the true purpose of the quest . </Td> </Tr> <Tr> <Th> 35 </Th> <Td> 9 </Td> <Td> "Love in the Time of Dragons" </Td> <Td> Alice Troughton </Td> <Td> Jake Michie </Td> <Td> 6 November 2010 (2010 - 11 - 06) </Td> <Td> 6.90 </Td> </Tr> <Tr> <Td_colspan="7"> When Alice, a physician and Gaius' old love, returns to Camelot, he is smitten again . However, she brings a Manticore with a plan to kill Uther with poison from its scorpion tail . Merlin tries to tell Gaius, but he won't listen . </Td> </Tr> <Tr> <Th> 36 </Th> <Td> 10 </Td> <Td> "Queen of Hearts" </Td> <Td> Ashley Way </Td> <Td> Howard Overman </Td> <Td> 13 November 2010 (2010 - 11 - 13) </Td> <Td> 7.37 </Td> </Tr> <Tr> <Td_colspan="7"> Morgana has visions about Gwen being crowned as Queen of Camelot . Morgause tells her that to prevent this she must find a way to split Gwen and Arthur up . Morgana first leads Uther to Arthur and Gwen's date, causing the king to banish Gwen from Camelot . When it seems that Morgana's plan has backfired, Gwen is accused of being a sorceress thanks to evidence that Morgana planted in Arthur's room . Merlin uses an ageing spell to disguise himself as the real culprit and save Gwen . </Td> </Tr> <Tr> <Th> 37 </Th> <Td> 11 </Td> <Td> "The Sorcerer's Shadow" </Td> <Td> Ashley Way </Td> <Td> Julian Jones </Td> <Td> 20 November 2010 (2010 - 11 - 20) </Td> <Td> 7.42 </Td> </Tr> <Tr> <Td_colspan="7"> As another tournament descends on Camelot, a young man known as Gilli sets his sights on victory . Gilli uses magic in the tournament to win his fights, and by doing so he begins to realize the true strength of his powers and what glory he could possibly use them for . Meanwhile, Morgana manipulates Uther and Arthur into competing against each other . </Td> </Tr> <Tr> <Th> 38 </Th> <Td> 12 </Td> <Td> "The Coming of Arthur - Part 1" </Td> <Td> Jeremy Webb </Td> <Td> Jake Michie </Td> <Td> 27 November 2010 (2010 - 11 - 27) </Td> <Td> 7.12 </Td> </Tr> <Tr> <Td_colspan="7"> Merlin and Arthur must save the Cup of Life before it ends up in the wrong hands . They manage to get it, but quickly lose it to Morgause . With an immortal army on side, Morgause takes over Camelot . Merlin and Arthur secretly watch in horror as Morgana reveals her true allegiance (as well as her parentage) and is crowned Queen of Camelot . </Td> </Tr> <Tr> <Th> 39 </Th> <Td> 13 </Td> <Td> "The Coming of Arthur - Part 2" </Td> <Td> Jeremy Webb </Td> <Td> Julian Jones </Td> <Td> 4 December 2010 (2010 - 12 - 04) </Td> <Td> 7.67 </Td> </Tr> <Tr> <Td_colspan="7"> Morgana has taken Uther's place on the throne, while Uther sits defenseless and alone in the castle dungeons . Gwen and Sir Leon escape from Camelot to join up with Arthur and his friends in exile . Despite the impossibility of facing an immortal army, they plan a counter attack to rescue Uther and Camelot . </Td> </Tr> </Table> <Tr> <Th> No . overall </Th> <Th> No. in series </Th> <Th> Title </Th> <Th> Directed by </Th> <Th> Written by </Th> <Th> Original air date </Th> <Th> UK viewers (millions) </Th> </Tr>

When does arthur find out about morgana being evil