TV Faced with the impossible mission of filming Doctor Who's 50th at London landmarks in secret, the crew evidently decided that rather than do everything in Cardiff against a green screen, they'd simply film what they need, fans with camera phones and paps be damned.
Presumably this is on the back of their work at Central Park in New York last year which ended up offering a massive amount of publicity for the show. They've also, rather cleverly, released some videos of the stars on the set saying how lovely it all is:
So that's Ingrid Oliver we can also add to ever growing cast list along with Jemma Redgrave. That scarf must just be a kiss to the past rather than implying she's the Fourth Doctor's daughter or anything.
Is Strax a sleeper agent? Field report? What?