The Doctor jaunts back to 1505 in order to ask Leonardo Da Vinci why he painted so many copies of the Mona Lisa and runs into another mystery. A man – Captain Tancredi – who not only looks exactly like Scarlioni, but also has all of his memories ….

Peter Halliday is good fun as the harassed guard captain. Barely recognisable as the sadistic Packer from a decade earlier (maybe it was the hat) this is a character who’s no match for the wily Doctor.  Even if Tom delivers one of the least convincing punches ever seen to knock him out.  He should have taken lessons from Tom Chadbon.

Luckily for us, Tancredi is a very garrulous sort of chap who’s happy to stop and explain the plot (“the knowledge will be of little use to you, since you will shortly die”). This is something of a cop-out, but also a dramatic convention – how often does the villain not kill the hero, but instead chats to him about his wicked plans?  Possibly Douglas Adams intended this to be an obviously groanworthy moment or it might just have been that the clock was ticking and he had to make an info-dump and quick.

Back in 1979, Romana and Duggan are too late to stop the Mona Lisa from being stolen. I haven’t mentioned how wonderful Lalla Ward’s Romana is yet, which is a terrible oversight.  She’s wonderful.  Whilst the debate about a female Doctor continues to rumble on, it’s plain that we pretty much had one right here – Romana as the Doctor with Duggan as her dim companion?  Yep, I’d go for that.

The dialogue continues to sparkle as Romana propounds a theory.  “Perhaps Scarlioni has discovered a way to travel in time. Yes, perhaps he went back in time, had a chat to Leonardo, got him to rustle up another six, came forward in time, stole the one in the Louvre, and now sells all seven at enormous profit. Sound reasonable?”  To which poor Duggan can only respond that when he used to do divorce cases they were never like this!

Isolating the Doctor from pretty much all of the 1979 action during this episode obviously allowed Romana to take his place. She’s a more than adequate substitute, as seen when she dices with Scarlioni, but there’s still a hint of her inexperience (touched upon during the Key to Time season, where it was stated on more than one occasion that her knowledge lacked the Doctor’s practical edge).  It’s hard to imagine the Doctor agreeing to build Scarlioni a time-field interface so readily, but since it needed to be done to advance the plot and also because Duggan was threatened it doesn’t make her seem too dim or easily duped.

One of my favourite moments of the entire story occurs right at the end of the episode. After Kerensky ages and dies before the horrified gaze of Romana and Duggan, the Count flashes them an amused stare.  There’s something about Julian Glover’s coolness which appeals immensely.