Every series get's a little bit darker, and this newest trailer is no exception.

The trailer was shown at the San Diego Comic-Con and left lot's of tantalizing clues and unresolved questions for fans.

Is Moriarty really dead? Or does Sherlock and his trusty side-kick have to watch out for other foes?

The season won't premier till 2017, but this trailer leaves fans with a taste of the action to come.