This review contains no plot spoilers.
British mythical history is a rich resource that television loves to mine. Doctor Who is arguably a new vein; the adventures of Robin Hood an old one. None, though, is quite so old as King Arthur of Camelot. Merlin delves into Camelot from, obviously, Merlin's point of view- through the eyes of a young man with rather astonishing skills.
I think that the makers would have had to try very hard to leave nothing worth watching, but there is more than just competence here.
First, some parametres. Merlin is a light ahistorical 'family' show- more so than Robin Hood or especially the new Doctor Who ever were. The pilot, at least, has a relatively simple story and the magical aspects usually lean towards the humorous/corny, a fact not due to the special effects themselves, but to the way they are included. However, the show is well written, well-acted, well-produced, interesting, funny and entertaining.
A few things stand out for me in this first episode of what promises to be an excellent show. The first was the dialogue: it is good. For a show that delves into high fantasy (an area avoided by most television due to the difficulties of pulling off the word 'destiny'), having solid dialogue is of the utmost importance. Merlin has managed to do this and it gives the entire production- the acting especially- something solid to stand on.
Or perhaps it is the actors that can make the dialogue sound convincing. This is not a deep drama, but the cast is one that could easily handle something far more complex. We have Buffy's Anthony Stewart Head playing a rather more believable-and-interesting-than-normal 'bad' character. I was delighted to see Eve Miles (Torchwood, Doctor Who) also being highly convincing, and Richard Wilson, who I didn't recognize but has an extensive, high-quality and wide-ranging repertoire of television and film experience that is clear in the first few minutes of his appearance.
Merlin himself, the keystone of the show, is another Doctor Who actor, Colin Morgan. He's got little beyond Doctor Who in his imdb profile but the choice was precisely the right one. He's captured a youth delighted with a new city, over his head in a number of ways but intelligent and confident to act as he sees fit. He brings humor and believability to the role of Merlin and tightly ties the show together.
I can see how this show could disappoint some. It pays no little to other Arthur myths or timelines, or to the real history of Britain. It is not as dark as it could be, nor as complex.
And yet this first episode is solidly written and acted, highly entertaining and hints at greater things to come. It is an apologetically modern, fantastical take on a tale rich with detail to pick and choose from. I hope it continues to develop into its own version of the King Arthur legend, to draw on complex themes alongside the childlike glee it has begun with.
I'm looking forward greatly to the next episode, and what more can you ask for?