So there we have it – Jodie Whittaker has been unveiled as Peter Capaldi’s Doctor Who successor, and the world has been left reeling at the casting of the first female Doctor. 

But perhaps we shouldn’t be so surprised – because some fans have speculated that the idea of a female Doctor has been teased by the production team already. 

Just take a look back at the tease for the casting announcement that was released on Friday night. Notice anything interesting about where all those “13s” keep appearing?

No? Well, some online fans noted that a LOT of these objects and locations relate to women. Obviously the Statue of Liberty depicts a woman, No 10. Downing St is currently home to Britain’s second female Prime Minister and the Sahara desert (where the number 13 appears in the sand) is taken from a woman’s name. And even the iPhone could have a female connection through Operating System Siri, the “voice of the phone” usually programmed as female.

Not convinced? Keen to point out to us that these are all pretty tenuous and that there’s nothing really associating women with Stop signs or the White Cliffs of Dover? Well, you may be right – but there might have been a few other hints recently.

Just look at this dialogue from penultimate series 10 episode World Enough and Time, which saw the Doctor (Peter Capaldi) reveal to Pearl Mackie’s Bill (and remind the audience of) the Time Lord’s more relaxed approach to gender (via discussion of Michelle Gomez’ Missy).

DOCTOR: She was my first friend, always so brilliant, from the first day at the Academy. So fast, so funny. She was my man crush.

BILL: I'm sorry? 

DOCTOR: Yeah, I think she was a man back then. I'm fairly sure that I was, too. It was a long time ago, though.

BILL: So, the Time Lords, bit flexible on the whole man-woman thing, then, yeah? 

DOCTOR: We're the most civilised civilisation in the universe. We're billions of years beyond your petty human obsession with gender and its associated stereotypes. 

Of course, this dialogue also helped to set up the return of John Simm’s earlier incarnation of Gomez’ Master, who actually dropped the biggest hint of all in series finale The Doctor Falls.

MASTER: Do as she says. Is the future going to be all girl?

DOCTOR: We can only hope.

So was this a real hint to the Doctor’s first female incarnation? A random piece of dialogue with no relevance to the recasting? Or somewhere between the two, an acknowledgement of the debate by departing showrunner Steven Moffat even thought he had little inside knowledge of Whittaker’s casting?

We may never know for sure (although it’s probably the last one) but one thing is certain. No matter what changes in the show, when it comes to Doctor Who fans will ALWAYS go the extra mile in speculation. Heartening stuff.

Doctor Who returns to BBC1 this Christmas