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1. Dynamite and a big red presidential button
Could the Doctor be set to become Lord President of Gallifrey? Or will he need to intervene in US political affairs before someone hits a big red button?
2. A forbidden number
Who knows why the number 507 is forbidden? Perhaps it's a reference to the famous 507 faces line Russell T Davies wrote for The Doctor in The Sarah Jane Adventures?
The former showrunner decided to flout the 13 regenerations rule in The Death of The Doctor, when the Time Lord revealed he could have 507 faces.
"507 – I could not resist!", he told SFX at the time. "I was hooting. It'll never stick, though. That 13 lives is stuck in people's heads. It is, isn't it funny? Yet they only said 13 once or twice."
3. A copy of Northanger Abbey – is Bill an Austen fan?
Jane Austen is no stranger to Doctor Who. The author has been referenced on numerous occasions, particularly during Clara and the Doctor's run in the Tardis.
Could Bill be studying literature at university? Or (and we're REALLY going out on a limb here) could she follow in Clara's footsteps and rate Jane's pranking and snogging skills?
It's also interesting to note that Austen originally titled Northanger Abbey Susan, which coincidentally is the name of the Doctor's granddaughter and original travelling companion. In a clip from series 10 released last week, we see a framed photo of her on the Doctor's desk while he's talking to Bill. And it sounds a lot like he's comparing them to one another. Could it be he sees something of his first companion in his latest one?
Peter Capaldi, Pearl Mackie and Steven Moffat are all set to appear at the Radio Times Television Festival from April 7th to 9th
See the full line up of events here
4. A masterful example of a milliner’s craft
Masterful? Surely this Mary Poppins-style hat can only belong to one person, the Doctor's Time Lord adversary also known as Missy...
5. Just the right helmet for an airtight situation
Another familiar piece of headgear here. Bill and the Doctor both don helmets in episode 5.
6. A bill of fare...or should that be fair?
If you look rather closely at the poster you'll see the word 'elephant' so this surely means Bill and The Doctor will be attending London's 1814 Frost Fair. The Thames was known to freeze over in those days, with ice thick enough to support a full scale fair. And in 1814 in particular, an elephant walked on the frozen river.
Solve clues 7 to 13
Leave your own theories about the clues in the comments below...