Prequel video of new 'Doctor Who' episode posted online - watch
New teaser clip shows Matt Smith's Doctor on the hunt for new assistant Clarea...
The clip, which is set just before the events of The Bells Of St John - the first episode of the second half of the show's seventh series - shows Matt Smith's Time Lord feeling forlorn due to his failure to find his new assistant Clara.
Clara, played by Jenna-Louise Coleman, will have her first full adventure with the Doctor in The Bells Of St John, which will be broadcast on March 30. The new sidekick with a mysterious past has appeared in previous episodes of the drama including Asylum Of The Daleks, and the Christmas special The Snowmen.
There are eight new episodes of Doctor Who coming in 2013 after the show went on a mid-season break last year following the departure of the Doctor's much-loved companions Amy Pond and Rory Williams. There will also be a 50th anniversary special which will air on November 23 - you can see a trailer for the episode by clicking below.