It's a very happy St Patrick's day for Doctor Who fans around the world because the BBC have only gone and dropped a brand new trailer for the second half of season 7! We know, we know, in reality this show is well beyond 7 series, but that's what they're calling it and we certainly ain't complaining.

The latest vid-yoh teases "the only mystery worth solving", and it seems the mystery in question is none other than The Doctor's new assistant, Clara Oswald. *insert joke relating to man's desire for Jenna Louise Coleman here*. Seems the pair are set for quite the adventure when they return with 'The Bells of St John'. Steven Moffat's written the episode himself, so it's sure to be a humdinger.

Catch the latest episodes Doctor Who on BBC One from March 30th.