When Doctor Who returned to BBC ONE in the U.K. earlier this year, the build-up to the first new episode in 16 years was accompanied by a series of spine-tinglingly exciting 15-second teaser trailers (or "stings" as we Brits call them), introducing a whole new generation to the TARDIS, The Doctor's assistant (in the shape of Billie Piper), and the enigmatic time-traveller himself, played expertly by Christopher Eccleston.

Now that Eccleston has transmogrified into my fellow-Scots actor David Tennant, the BBC is eager to make sure the formula which rocketed the series back up to the dizzy heights of success Doctor Who attained in the 60s and 70s continues to work -- and they've started another teaser campaign for the build-up to The Christmas Invasion, a special introductory episode that will air on Christmas Day here in the U.K.

The first sting is available to view on the BBC website, which will also be repeated on BBC ONE tonight, to be followed by three more on the subsequent Friday nights leading up to Tennant's inaugural episode on 25th (not counting the BBC Children in Need series-link special).