In which things started to fall into place. Actually that would probably be my one criticism of this Doctor Who adventure: for four out of the six episodes it's been something of a mass of conflicting plot threads & divergent possibilities. In fact, in common with many of these multi-part series, I would think it could be a four-parter as a maximum. I'm aware that I also tend to say this about Sapphire & Steel, so it's possible that it's me reacting to the pace of 1970s TV by wanting it to speed up a bit.
Of course, this being Doctor Who, the answer to what's going on is weird. Of course the Peking Homoncurus has to be a 'dashed queer story': I like the way Litefoot easily falls into the Watson role. The other caricatures - steam laundries & what have you - come thick & fast. Jago envisages the situation as a business opportunity; while I love the way his showmanship comes to the forefront when he meets Litefoot. I haven't heard any of Big Finish's adventures of these pair - & am frankly wary of Big Finish on account of The Avengers - but can see that they would be a perfect amateur sleuthing partnership.
Despite a somewhat standard detective story plot - stooges get caught by the baddies, our hero has no idea where they are but we know he'll rescue them in the final episode - there is a genuine sense of suspense when Jago & Litefoot are imprisoned.
Isn't it fortunate for the Doctor when he chances to find the trionic lattice, the necessary key to the cabinet, absentmindedly left lying around? Lucky break, that.
My favourite line:
'"Eureka"'s Greek for "This bath is too hot".'