What do the people want? A combination of Lord of the Rings and Doctor Who. This seems to be the principle upon which this episode of Merlin is written, and I’m not sure it’s a principle I can disagree with. After lurching entertainingly around medieval legends and high-school romance plots for most of the season, the show seems to have snapped into a more straightforward fantasy mode. We open with Morgause in a ruined castle chanting near some spiderwebs, because if you’d managed to sign a performer like Emilia Fox, who can do this kind of nonsense without either winking at the camera every ten second or being plain annoying, you’d give her the opening scene too.
The chanting follows the Merlin model of spell-casting, which is rather like an Anglo-Saxon version of Harry Potter’s Latin magic – it sounds enough like the language to sound convincing, but not so much that you can’t get the general gist if you only speak English. Very articulate, gel, Moragause, but I can’t help feeling that raising undead knights isn’t the purpose for which Captain Awkward is always telling us to “use our words”. The knights awake, and move around underneath their cowls with wide, slightly slo-mo gestures. They were once knights of Camelot, before a sorceress lured them into her service with magic and their humanity eroded, so now they are oversized ragged-cloaked undead warriors with massive swords and an air of horrific melancholy, but actually there are seven of them, not nine, so it’s not actually the same thing as the Nazgûl at all and you can’t say it is because OMG can you not count or something? They’re almost certainly the best part of this episode, and when they’re not looking a bit like the Ringwraiths (er, numeracy, much? Is IX the same as VII, if you need it in letters?) they’re looking quite like The Man In The Iron Mask, or indeed like the cybermen in discount hoodies.
When news of their oddly synchronised clanking of spurs and gloomy dismounting of horses reaches King Uther (Anthony Head) asks Arthur to take some men and ride over just to check it’s all a rumour. Because this is something his father has asked him to do, as opposed to forbade him from doing, Arthur doesn’t want to. But there are duties pertaining to the heir of Camelot, and even as they argue, another one is being hastily scribbled onto the bottom of the increasingly crowded Lyste of Ancestrall Obliggatyons For Princes by a scribe who knows how to make the right blend of cold tea and builder’s sand to get the correct aged-looking effect. Off he goes, with Merlin as camp follower.
Meanwhile (what did people ever use that word for before TV recapping was a thing?) Camelot’s one-woman fifth column is busy betraying up a storm. Morgana (Katie McGrath) is feeling the pull of family ties, and sneaks out to have a sisterly chat with Morgause and agonise over why she didn’t kill Uther when she had a chance. Morgause, because sisters are like that, enchants her so that when she returns to Camelot everyone around her falls under the influence of a sleeping sickness. It’s supportive stuff: you suspect your sister is feeling people in her castle don’t listen to her and find her tedious so you magically ensure they literally fall asleep whenever she’s around. Hil-LAIR.
Discovering that the Knights of Medhir are in fact not a rumour, Arthur and Merlin allow their own men to die of a combination of “well, I never!” and massive sword-based trauma, and flee back to Camelot to find everyone asleep. All but Morgana, who doesn’t know why she’s still awake, but knows that something odd and Morgause-scented is definitely kicking off. Whilst racing against time to find a solution to the spell/sickness before the Knights of Medhir over-run the castle, Merlin falls back on the old dependable option and enchants a dragon to channel John Hurt. But John Hurt is having none of it, and wants his freedom (I don’t blame him, I’d be well vexed if I had to spend whole episodes hiding in those damp caves doing a ventriloquist act with a giant lizard whilst everyone pranced around upstairs) in exchange for telling Merlin to kill Morgana to break the enchantment.
The rest of the episode has a very Doctor Who feel to it, for reasons I can’t quite pin down. I suppose there’s the mysterious virus affecting them one by one, the beginning to not trust each other, the implacable metal foes and the fact that the castle full of sleeping people has an air of one of those Gothic spaces where sci-fi and fantasy blur into one another. Either way Merlin tricks Morgana into drinking hemlock, Morgause arrives too late to stop him, and they all live fulfilled lives for the rest of their days. The rest of their days may of course consist of about seventy-two hours, since Merlin has just released a saurian sociopath with the ability to breathe fire…
 Yes, I am braced for the complaints from Anglo-Saxonists. I accept that OE is indeed English, but you know exactly what I mean and your quibbling is holding up the bit with the undead knights, so is this little diversion really benefitting anyone?
 No, you feel free. Don’t mind me, I’ll hang around whilst you make stupid puns, it’s not like I have another paragraph to get on with or anything. Honestly…