The TARDIS dematerialises from one pyramid and lands at another, but the similarities to The Keys of Marinus end there. Within the first few lines of dialogue the audience has been alerted that this is going to be another history episode. And a couple of lines later John Lucarotti has set up the whole thrust of the story:

Susan: The little I know about [the Aztecs] doesn’t impress me. Cutting out people’s hearts.

Barbara: Oh, that was only one side to their nature. The other side was highly civilised.

Susan: The Spanish didn’t think so.

Barbara: They only saw the acts of sacrifice. That was the tragedy of the Aztecs. The whole civilisation was completely destroyed, the good as well as the evil.

The episode revolves around this dualism. Representing the benevolent, civilised side of the Aztecs is Autloc. The malevolent, evil side is embodied by Tlotoxl. Many commentators have compared John Ringham’s performance to Olivier’s Richard III, and it’s fair. Tlotoxl does seem ‘determined to prove a villain’ right from the outset. Hunchbacked, dripping venom, he’s instantly dismissed as ‘the local butcher’ by Ian and the Doctor. And Tlotoxl wastes no time in plotting against the new arrivals, dispatching Ian to face the warrior Ixta. This is a weakness in the script: Tlotoxl is simply evil – there’s no hint of any motivation here, not even Yartek’s lust for power. Had his villainy been prompted by Barbara’s interference in a sacrifice, there would at least be some explanation. Ringham’s decision to play this boo-hiss baddie as Richard III makes sense given there’s nothing else there to work with.

Elsewhere, Lucarotti focuses the episode around a series of duels, all verbal at this stage – Ian versus Ixta, and the Doctor versus Barbara. The Doctor’s mantra is ‘don’t interfere’, ‘you can’t rewrite history, not one line!’. Barbara disagrees, planning to change history and save the Aztec civilisation, which leads to a stand-off at the top of the pyramid. There’s at least a sense that this adventure might be about something. By the end of the episode Lucarotti has established several conflicts: Autloc versus Tlotoxl; Ixta versus Ian; Tlotoxl versus Barbara, and the Doctor versus Barbara, and with all these agendas in play there seems much more potential than at the end of The Roof of the World.

Comparisons to Marco Polo are fair: obviously Lucarotti wrote both; John Crockett directed The Wall of Lies, and Barry Newbery designed both stories. The Temple of Evil probably gives us the clearest sense of what the previous historical must have looked like. Mirroring Marco Polo’s Marco and Tegana, there are essentially two main ‘guest’ characters, one of whom has an enquiring and rational mind, the other is superstitious and conniving. Both begin with the TARDIS crew being mistaken for spirits, although in this case Barbara, predating Missy by 51 years as the show’s first transgender reincarnation, gets quite a lot more to do. However, the tourism of the earlier story isn’t evident: this isn’t a journey along the route to Peking, but an opportunity to change the course of history. In the sense that it’s about escaping destiny rather than Cathay, or Skaro, or prehistoric Earth, this has the potential to get very interesting.

Other things to notice: Hartnell is really not on top of his lines this week, stumbling over several and over-talking William Russell in the Garden of Peace. Maybe the Doctor’s head really has been turned by Cameca.

Next episode: The Warriors of Death