YAAAAAAAAS! This is the best news EVER!
According to a particular Twitter update from a certain co-creator by the name of Mark Gatiss, filming has OFFICIALLY begun!
"Element-hairy, my dear Watson! #Sherlock"
Hairy? What does he mean by Element-hairy?!?
Well, it could have to do with the funny little picture of a certain important filming slate that he included with the tweet: