Same team, same mysteries, different era.

Benedict Cumberbatch and Martin Freeman return as Sherlock Holmes and Dr. John Watson in the first full trailer for their return to Baker St.

The duo finds themselves in the throws of 19th century London where they must put their skills to the test for reasons unbeknownst to us, so far.

Another mystery from the Sherlock team?

The premiere date.

Take a gander at the trailer below, and let us know what you expect to see from this perplexing special episode.