A young Druid named Daegal (guest star Alfie Stewart, pictured above) arrives at Camelot seeking out Merlin’s help. Daegal claims that his sister is ill and only Merlin can save her. After a little bit of reluctance, Merlin eventually heads out on a lengthy journey to the Valley of the Fallen Kings, where it is revealed he has been lured into a particularly deadly trap.

Back in Castle Camelot, Arthur’s is preparing for a visit from the Sarrum of Amata (guest John Shrapnel) in his latest attempts to unite the lands of Camelot. Arthur believes he can talk the Sarrum around, but Gwen has her own plans. Of course, Gwen is still Morgana’s “puppet” and the latest assassination attempt of Arthur is put into action.

Unlike last week’s familiar plot, this is the more interesting episode of the two. For most of the story Merlin is powerless to save Arthur. As we watch the Arthur plot play out, Merlin is having a really bad time away from the castle. It makes for some tense viewing and you really begin to question just how both Merlin and Arthur will get out of this one alive. Colin Morgan really sells the pain and anguish that he is going through. The nature of the plot also brings up Merlin’s personal life and it’s good to see the writers haven’t completely forgotten that aspect of his character.

With Merlin away, it falls to Gaius to perform some of his servant duties. This leads to a comedy scene that is mildly amusing (undoubtedly for younger viewers) but it’s another moment that feels a bit out of place with the overall tone of the rest of the episode. And are we really supposed to believe that Arthur still can’t get himself dressed at his age? On the plus side though, we get to see more of Gaius, who hasn’t had a great deal to do this year.

The intriguing plot arcs that were set up in the opening two-party have largely gone by the wayside for a good deal of the run so far. Once again Mordred is almost entirely absent, with not even a line to speak. But at least there’s some furthering of the Morgana storyline. We finally find out a bit more about her two-year captivity between Series 4 and 5; learning how she was caught in the first place and also how white Dragon Aithusa became so deformed.

As for the two main guest stars this week, veteran actor John Shrapnel puts in a suitably sinister performance as the Sarrum. The scene where he describes how he captured Morgana is one of the highlights of the episode. Alfie Stewart is good too as the naive Daegal and resembles a young Merlin in many ways. The two do eventually form a nice, if shortlived, bond.

It’s a stronger episode than last week’s overall, and it’s good to see some earlier plot threads coming together. Let’s hope it continues.

8/10

The episode airs Saturday 24 November 2012 at 8pm on BBC1.