It’s Gwen and Arthur’s anniversary, but celebrations are cut short when Arthur is thrown off his horse and ambushed by some bandits. Arthur manages to get away with just a scratch and learns that someone sabotaged his horse beforehand. The blame goes to stable-hand Tyr Seward (guest starring Game of Thrones’ John Bradley in a short role) and after evidence is found at his home, he is reluctantly sentenced to death by Arthur. It’s up to Merlin to prove Tyr’s innocence but it’s not easy as the real perpetrator is within Camelot’s walls.

Of course it doesn’t take a genius to work out that Gwen is the one really responsible. As last week’s cliffhanger revealed, Gwen has been turned and is now doing Morgana’s evil bidding. Merlin, as usual, seems to be the only one that has noticed that the Queen is acting a little strange since her return from the Dark Tower. Everyone else initially brushes off his concerns as a result of grief from Elyan’s death. However, there’s a pleasing moment later when Arthur openly questions if Merlin has been right all along.

Some fans have complained that this year hasn’t focussed on Merlin a great deal, with all attention going to Arthur. This episode may satisfy those fans since Merlin is given much more to do here as he races against the clock alone trying to stop Gwen. Only Gaius helps him when he gets into a tricky spot. Soon enough, Merlin works out that Gwen is involved in another attempt on Arthur’s life. However, Gwen is a tough foe to crack.

It’s certainly quite alarming seeing Gwen performing cruel acts. There’s a particularly shocking moment quite early on leaving the Queen with blood on her hands. Will she ever realise what she has done? Not here, but whatever happens, Angel Coulby is clearly relishing the chance to play a different take on the character. Morgana is only in a few scenes and one of them is under heavy aging make-up.

Merlin too dons his older guise once again, although he is only in a couple of scenes that are purely played for laughs. Unfortunately this comes late on in the story and the sudden silly antics are a bit jarring as they do take away from the immediate drama. For the amount of time Old Merlin appears, it wasn’t really worth putting Colin Morgan through hours of make-up. However these comic mishaps are made up by some excellent acting from Morgan again in the final scenes.

It’s a decent episode then, but the biggest problem facing it is the feeling of familiarity. The central idea here has been explored in the show a few times now. And the interactions between Gwen and Morgana are evoking the scenes of her and Agravaine from Series 4. Hopefully things will get shaken up a bit as we continue into the final half of the series.

7/10