As teaser trailers go, this is a bit of a tease.
On Friday night, the BBC followed their repeat of the final episode of Sherlock series 2 with a short advert for the forthcoming third series. It's all very mysterious, but *spoiler* Sherlock is there - which is pretty big news for all concerned. Having said that, a series called Sherlock without Sherlock would have been a bit weird.
No air date has yet been given, but it is thought filming on the first two episodes is complete, with the third well underway, so fingers crossed for an autumn appearance.