Ian pleads with Tegana. “Let us all go, I appeal to you. What possible difference could it make to you? You hate Marco.” This is another indication that the emphasis in these early stories is very much centered around the TARDIS crew as they seem to care little about what Tegana might do to Marco and Ping-Cho once they leave. This is a hallmark of the early historical stories script-edited by David Whitaker (and is also a feature of his own serial The Crusade).

At times during these early historical stories (especially in Lucarotti’s next script, The Aztecs) the Doctor is a very passive character who is unwilling to get involved in local difficulties. This is possibly not because he shouldn’t, but because he can’t (the famous line in The Aztecs – “you can’t rewrite history, not one line!” – is something we’ll touch upon when we reach that story). Here, it might be more disinterest than a fear that he’ll somehow damage the delicate thread of space-time history.

Ian protects Ping-Cho by telling Marco that he stole the TARDIS key. We then have another scene where Ian pleads with Marco to hand back the TARDIS – and this time Ian tells him the truth (that the TARDIS can fly through time and space). Marco responds that he’s heard of many strange things, including a stone that burns (coal). “In Cathay, we call it the burning stone. And if a stone burns, why not a caravan that flies? Birds fly. I have even seen fish that fly. You are asking me to believe that your caravan can defy the passage of the sun? Move not merely from one place to another, but from today into tomorrow, today into yesterday? No, Ian. That I cannot accept.”

Although he can believe in a burning stone, a flying caravan and even flying fish, it seems that the concept of time-travel is a step too far. Marco then tells Ian that he knows he didn’t take the key and he only said it to shield Ping-Cho. It’s a clever piece of scripting as it demonstrates to Marco that Ian is capable of lying, which means that he can’t believe his tales of time-travel. If he did, then he would have handed the TARDIS key over (although given all he’s done so far, that seems a little improbable).

Ping-Cho, unwilling to marry a man old enough to be her grandfather, runs away – back to the Cheng-Ting Way Station. It’s a slight plot contrivance that of all the people she could meet, it’s Kuiju (the man commissioned by Tegana to steal the TARDIS). You’d have thought that the eyepatch and the monkey would have been strong indications that he was a wrong-‘un, but Ping-Cho, innocent girl that she is, mistakenly believes he’s an honest man and hands over all her money to pay for her passage back home.

That she should be robbed by the man who’s stolen the TARDIS is a bit of a coincidence – especially since it doesn’t really impact the plot. Ian has received Marco’s blessing to search for Ping-Cho and once he finds her and discovers that the TARDIS has been stolen the pair of them set off to find it.

The others finally get to meet the mighty Khan, who certainly receives an impressive buildup –

Silence! Those who dare to come before the sight of the great Kublai Khan, kow-tow. Kow-tow before the War Lord of War Lords. Mighty and fearful in his strength. Kow-tow before the Ruler of Asia, India, Cathay and other territories. Kow-tow before the Master of the World.

The eventual reveal that Kublai Khan (Martin Miller) is a little old man suffering from gout is amusing – but Marco is quick to tell the others that whilst the Khan is not the mightiest War Lord ever, he’s definitely a skilled administrator. And its his organisational skill, rather than his military might, that has seen his Empire grow – so it would be wise not to underestimate him.

His meeting with the Doctor has a nice touch of comedy – with both men suffering numerous aches and pains, plus the Doctor demonstrating his singular lack of respect for authority (a trait we’ll see time and time again over the years). The Khan, rather than expressing annoyance at the Doctor’s testiness, instead embraces him as a brother. Slightly implausible maybe, but it sets us up nicely for their interaction in the next episode.

Ian and Ping-Cho have found Kuiju and the TARDIS, but so has Tegana (who was given leave by Marco to track Ian down). At last it seems that Tegana has the upper hand – he can take the Doctor’s caravan and then dispatch Ian and Ping-Cho. What could possibly go wrong?