The Sentinels of the New DawnSynopsis :
Some time after leaving UNIT, Liz Shaw calls the Doctor to Cambridge University, where scientists are experimenting with time dilation. The device hurls them to the year 2014 and a meeting with Richard Beauregard, heir to the Beauregard estate.
Yet there's something rotten at the core of this family… The seeds of a political movement that believes in a new world order.
The Sentinels of the New Dawn are stirring and its malign influence will be felt for centuries to come... Casting :
Liz Shaw - Caroline John
Richard Beauregard - Duncan Wisbey
Source : http://tardis.wikia.com/wiki/The_Sentinels_of_the_New_Dawn_%28audio_story%29