The Conscience of the King is a fascinating, layered episode which operates in a much more morally ambigious universe than many Star Trek stories.

Dr. Thomas Leighton (William Sargent), an old friend of Kirk’s, calls the Enterprise to Planet Q. Leighton is convinced that the noted Shakespearian actor Anton Karidian (Arnold Moss) is actually Kodos the Executioner. The former governor of the Earth colony of Tarsus IV, Kodos was responsible for the massacre of over 4,000 people twenty years earlier (both Leighton and Kirk were eyewitnesses).

There’s a notable WW2 analogue which seeps through the episode. Kirk initially believes that Kodos is dead, although Leighton is far less sure (“a body burned beyond recognition?”). That’s a clear link to Hitler, although the notion of Kodos masquerading under a new identity also points towards any number of senior ex-Nazis who fashioned new lives for themselves after the fall of Berlin in 1945.

There are several disconcerting moments. The first occurs right at the start – instead of the familiar opening shot of the Enterprise zooming through space, we focus in on Karidian performing on stage as Macbeth. And the fact that Leighton’s first few scenes always shows him in profile seems at first to be a directorial choice, but this is not so …

After struggling a bit with Miri, Shatner’s back on top form today. He’s gifted plenty of good moments – for example, Kirk’s conflict with Spock. After Spock gently reminds him that he’s taken the Enterprise off course, Kirk snaps back that he’s well aware of this and “If my memory needs refreshing, Mister Spock, I’ll ask you for it”.

Although Kirk’s autocratic command style has been touched upon before, today’s episode digs even further into this topic. With Kirk still traumatised by the events of twenty years ago, he’s disinclined (at first) to listen to either Spock or McCoy.

That Spock is forced to seek Bones’ opinion is a nice little wrinkle (they’ve yet to really begin their games of one-upmanship but the tension between their differing approaches – logic on one side, emotion on the other – is still clear to see).

The atmosphere of The Conscience of the King is ramped up by having the key events take place at night. It’s a slightly strange concept and although Kirk explains that this is because the Enterprise duplicates the Earth conditions of night and day, it does seem hard on those working at “night”, since everything’s always going to be much gloomier for them ….

The strains of deep space exploration is mentioned several times.  Kirk admits that since the crew has been on patrol for a long time, the arrival of a group of theatrical players would help to break the monotony. Karidian’s daughter, Lenore (Barbara Anderson), later queries whether living inside the Enterprise has fundamentally changed the female crew (“made them just people instead of women?”).

Lenore might not be the best-drawn female guest character the series has ever seen, but she has her moments.  By now the viewer would have been primed to expect that she and Kirk would engage in a romantic liaison. And so they do, but there’s a sting in the tale – she’s clearly manipulating him to serve the best interests of both her father and herself (after the romantically manipulative Kirk of Miri, it’s slightly refreshing to see Jim outmanouvered for once).

Mind you, the leer he gives when he first claps eyes on her makes it hard to be that sympathetic towards him …

That both are dissembling throughout their relationship is another of those small touches which strengthens the episode.

We’re kept waiting for a while before Kirk and Karidian meet face to face. And although you know that eventually Karidian will be unmasked as Kodos (otherwise the story would lack a certain dramatic impact) this predictability isn’t a story flaw for me.

But if one were being picky, you could argue that it’s a staggering coincidence that one of the few remaining eyewitnesses to the massacre – Lt Riley – now serves aboard the Enterprise. Jim attempts to protect him (Leighton has already been murdered by this point) by moving him down to Engineering. But since someone nips down there and poisons his drink, maybe Kirk should have surrounded him with a group of redshirts instead …

The sparks which fly between Kirk, Spock and McCoy help to make this a top-tier series one episode. The Kirk/Lenore relationship might be a bit drippy on the surface, but that was the clear intention.

Arnold Moss’ performance veers towards the overblown (as does Barbara Anderson’s) but their broad playing feels at home in an episode which has a stage background. Kodos playing Karidian playing Macbeth ….