Nessun Dorma – the big aria from Turandot, translates as None Shall Sleep. Here in this story the themes explored in Swords, Tea and Turandot come back into play. Remember that The Doctor had said he would NOT let anybody be hurt for HIM.

If I knew somebody was being tortured to find MY secret I wouldn’t stand around like a lemon hoping they would kill themselves first and save my skin. I’d move heaven and earth to rescue them. And if I couldn’t… if the only thing that would save somebody else from torture and death is my surrender… then I’d give myself up first.”

So now that vow is put to the test when Jackie is being tortured to discover HIS name, just like the character in Turandot. And she makes the connection. She says “His name is love” – the answer given by the tortured servant girl in the opera. But The Doctor won’t allow anyone to suffer for him.

The 'secret' of The Doctor's name has been twice alluded to in the Second and Third series. In 2006, in Girl in The Fireplace, Madame De Pompadour says “Doctor who? It’s more than a secret, isn’t it?” And in The Shakespeare Code, in 2007, Lillith the Carrionite witch tries to use the ‘magic’ of names against The Doctor but finds that he ‘has no name’ – or at least not one her telepathy can. The latter rather confirms what The Doctor says in this story about a Time Lord’s name being used as a weapon against him.

And remember when Rose tested her sword skills in the same story? That, too, comes to fruition when she has to free him from the steel restraints. After that, it’s all over bar the shouting, as they say.

But The Doctor acquires himself a library. Watch out for that in the future.