In this story, Doctor Mordecai, unaware that his wife is still alive and a slave to Titus, wants to remarry. Luckily (!) a plague draws him to Rome, where his wife is living.
This story features another prophetic dream, which always makes me happy of course and is thoroughly appropriate for a story heavily featuring Aesculapius, who had a marked tendency to appear to people in dreams. Titus has had a dream about a Pandora's box being opened by a Prometheus, and he believes that it means an enemy of Jupiter will do something that will destroy Rome, and it's this puzzle that Flavia offers to try to solve.
Much of the story concerns a certain important box that one is not supposed to open. Josephus (yay!) tells the children about the Ark of the Covenant, which will be especially fun for any viewers who've seen Indiana Jones and the Raiders of the Lost Ark. I only saw that film for the first time a couple of years ago, and wasn't entirely paying attention, but even I developed a vague expectation that melting Nazis would somehow be involved in this story. I like the identification of the Ark with Pandora's box - this story makes much more interesting use of the Pandora's box story than most, which is lovely to see.
Titus continues to be portrayed as jealous and potentially very dangerous, even more so than in the books I've read, though of course I haven't read this particular one. I like this grey Titus, though sometimes it makes his acts of kindness seem stranger and less natural.
The sections where Flavia, Nubia and Lupus interrogate various doctors are rather fun, since ancient medicine is always good for a laugh if you're not actually victim to it, though unfortunately these sections are rather lost next to the much more important storyline concerning Mordecai and Susannah. Their reunion is genuinely touching, and of course, the television version has removed the unfortunate detail that Susannah left Mordecai for another man - here, she stayed behind to care for her sick father - so he has no reason to be angry, at least until Titus turns up. Titus is, unsurprisingly, Not Happy, and a nice tense scene ensues between the three, which ends up with Jonathan dragged off by guards again while Susannah suffers from poison inflicted by Berenice (who, historically, is the daughter of Herod Agrippa from I, Claudius, by the way).
Should have recognised the bad guy too - he once tried to eat Jill and Eustace in The Silver Chair. (He's a time traveller as well - he already calls the Flavian amphitheatre the Colosseum). That wasn't the only part that reminded me of The Silver Chair - the children are confronted with a brilliantly awful choice when they have to open the box which may or may not be the Ark of the Covenant in order to save Susannah (which, of course, they do, and it's the right choice, but it's a wonderfully horrible moment!).
I loved Lupus knocking out the bad guy with a slingshot - pure David and Goliath. And in this TV adaptation, poor Jonathan himself certainly isn't responsible - not directly anyway - for the (second) Fire of Rome, he's just in the wrong place at the wrong time. The bit where Lupus tries to tell the others where Jonathan is with no voice is also straight out of a nightmare, even if they do realise what he's saying, and very well done. Nubia's musical ability saves the day again too, which is nice.
Flavia is either very brave or very stupid when she decides to tell Titus he and his hubris are the problem, but luckily it works and he lets Susannah go, for he is a goody after all.
The episode ends with Miriam's wedding, which in this version, her mother is able to attend (in the books, Miriam is already married by the end of The Twelve Tasks of Flavia Gemina) so that's nice. In fact, several elements from the un-adapted Twelve Tasks are here, most importantly, Marcus Geminus' desire for Flavia to stop 'running wild' and get married. Only one problem - at the beginning of The Gladiators from Capua, everyone thinks Jonathan is dead! I guess in the book they weren't able to find him in the fire? And Susannah is still with Titus? Hmm, I think a little digging around on the internet is in order...
Edited to add: Looks like Twelve Tasks has been adapted, in series 2 - it's just the wedding and the first mention of Flavia's own marriage that have been moved!