Conspiracy opens with another clandestine scene between the Doctor and Tavius.  The obvious joke is that the Doctor still has no idea what Tavius is talking about.  Tavius imparts the following vital information “I haven’t got long, so listen carefully. I’ve managed to get rid of that body and I don’t think anyone suspects. But if you delay your action, it will be safer.”

Every time that Tavius appears he hisses in a most unsubtle manner (in order to catch the Doctor’s attention).  It’s interesting that this bit of business wasn’t present in the script, so presumably Hartnell and Michael Peake worked it out in rehearsals.  Much later, Tom Baker’s willingness to treat the rehearsal script as simply a jumping off point for his own improvisations and suggestions would become legendary, but there’s no doubt that the four days rehearsal each episode was given during this period did allow for a certain leeway which sometimes benefited the story.

This episode sees the farce quotient ramped up another couple of notches as Barbara is presented to Nero’s wife Poppaea (Kay Patrick).  Poppaea’s not terribly impressed with Barbara, no doubt because she’s witnessed Nero’s instant attraction to her.  This wasn’t the first time that Barbara had found herself the object of male lust, although the others – Vasor in The Keys of Marinus and El Akir in The Crusade – weren’t played for laughs like Nero’s pursuit is here.

There’s a level of innuendo in the script for those who want to look for it (for example, Nero tells Barbara to “close your eyes and Nero will give you a big surprise”) and the farce element is at its most obvious as Nero pursues Barbara through the palace (she just avoids bumping into the Doctor or Vicki each time).  That Barbara remains unaware that the Doctor and Vicki are at court (and vice-versa) hardly seems credible – but that’s the whole joke and it’s delightful to see how the actors throw themselves wholeheartedly into the swing of things.

Derek Francis is a joy to behold in these scenes, he plays Nero as a little boy who’s anxious not to be found out.  But his other, more ruthless side, is demonstrated at the end of the episode as he watches Delos and Ian fight as gladiators.  Delos gains the upper hand and Nero has no hesitation in ordering Ian’s head to be cut off.  Whilst this seems at odds with the amiable, befuddled ruler we’ve previously seen, it actually fits in very well – Nero (like most Emperors) had lived so long with the gift of absolute power that he could be either cruel or compassionate, depending on his mood.  That so much power could be in the hands of such an unbalanced individual seems remarkable – but for all the comic stylings of the script, that part of The Romans is probably historically accurate.

Ian’s rather sidelined in this episode.  Locked up with Delos for most of the duration, he faces an uncertain future as a gladiator.  These scenes are most notable for the shots of two gladiators practising – unfortunately the way they fight is so feeble that it’s hard to imagine either would be capable of punching their way out of a paper bag …

Back at court, Vicki confesses to the Doctor that she might have poisoned Nero(!) which leads into another scene which is comic and dark at the same time.  The Doctor warns Nero and he passes his cup to the unfortunate Tigilinus (Brian Proudfoot).  Tigilinus drinks and plummets to the floor, dead.  “He was right” deadpans Nero as he shrugs and moves off.  What’s remarkable is that Vicki nevers seem to realise or indeed care that her actions cost the life of the court poisoner Locusta (Ann Tirard).

It’s finally time for the Doctor to demonstrate his non-existent skills as a lyre player.  “I would like to play my new composition in honour of this occasion. The music is so soft, so delicate, that only those with keen perceptive hearing, will be able to distinguish this melodious charm of music.”  Delightfully, he then proceed to play not a single note aloud, but since nobody wishes to admit that they lack the perceptive hearing required, everybody (including Nero) pretend to be entranced.  “He’s all right, but he’s not all that good” mutters Nero testily.  Brilliant!