It looks like Sherlock series 4 has started filming...

Whether or not that was the joke co-creator and star Gatiss was intending to make, Sherlock fans will be relieved that filming on the new three-part run of the detective drama is now under way.

They are likely to have to remain patient a while longer before they actually get to see the finished article, though – based on the timing of the last two series, and the recent special, we deduce that season four is quite likely to land on New Year's Day 2017.