sentences:  A single episode, "A Girl's Best Friend", was produced as a pilot for a proposed series, and broadcast by BBC1 as a Christmas special on 28 December 1981, but the series was not taken up.The basic premise of a series centered on Sarah Jane Smith was reused by Big Finish with the "" audio series and in the TV Series "The Sarah Jane Adventures" just over 25 years later.When it was decided that Billie Piper would leave the series at the end of Series 2, executive producer and head writer Russell T Davies considered giving her character Rose Tyler her own 90-minute spin-off production, "Rose Tyler