I think that the Doctor keeps doing that up and down action because he’s like I’ve seen you before I know I have. Where have I seen you before. Then when he turns around that moment of realization when he realizes that this is a reincarnation of Sir Percival and that it must mean Arthur is coming soon.
no wait what
this is what happens when two fandoms collide
This is what happens when a television network only has 20 actors on rotation…
Hush little fangirl, dont you squee
Moffat’s gonna kill off your OTP
and if next season he won’t return
BBC will find another ship to burn

I love the Beeb and their penchant for recycling actors.
What if like Colin or Bradley make a guest appearances on Sherlock?
Or better yet, they both guest star together. And they’d be this gay couple who asks Sherlock for help!