Although we learnt in episode one that the Tong of the Black Scorpion (“fanatical followers of an ancient Chinese god called Weng-Chiang”) seem to be involved in this devilish business, it now becomes clear that Chang is merely a subordinate character and his master – Weng-Chiang (or at least someone masquerading as him) – is the one directing events.

Weng-Chiang, or Magnus Greel to give him his real name, lives beneath the Palace Theatre.  Why he should do this – unless he’s a devotee of The Phantom of the Opera – is never made clear.  But since Chang is performing at the theatre it makes some sort of sense that Greel is close at hand – especially since Chang has been abducting girls off the street for him.

The science-fiction elements of the story now begin be pulled together as we learn that Greel is a refugee, afraid of the intervention of time-agents.  Why he wants the girls is also explained (“the disease grows worse. Each distillation lasts less than the time before”) and that until he recovers the Time Cabinet he’ll never be whole again.

It’s a remarkable coincidence that the Time Cabinet is in Lifefoot’s possession.  He’s unaware of its significance, regarding it as little more than a Chinese curio, although we’ll learn more about this in episode three.

For those who worry about such things, then the timeline of this story is very odd.  If Litefoot’s had the cabinet for decades, what has Greel been doing all this time?  We see that his body is in collapse, with only the life-essence from young female donors keeping him alive, so how has be survived during this period?  He can’t have been in London for more than a few weeks (based on the number of girls abducted) so are we really supposed to believe he’s only just decided that reclaiming the Time Cabinet might be a good idea?  And since Litefoot’s father was a notable member of the British government in China, surely it wouldn’t have been too difficult to work out that his family was the one gifted the Time Cabinet ….

Episode two sees the Doctor encounter Jago for the first time.  There’s a characteristic gear-change from the Doctor – to begin with he’s jovial – pretending to be a music-hall act ( “dramatic recitations, singing, tap-dancing. I can play the Trumpet Voluntary in a bowl of live goldfish”) – but in a double-heartbeat he turns serious.  As touched upon before, Tom could do this better than anyone and both he and Benjamin make these scenes – largely expository ones – sparkle.

Another signature moment occurs when Leela and Litefoot enjoy a bite to eat, with Leela’s table-manners being somewhat lacking.  Litefoot, the perfect host, elects to copy his guest in order not to make her feel awkward, which gives Trevor Baxter another nice character moment.