Doctor Who star David Tennant will appear in the new series of The Sarah Jane Adventures. David will guest star as the Doctor in the CBBC drama across two episodes this autumn. Investigative journalist Sarah Jane Smith, a one-time companion to the Doctor, will be reunited with her old friend in the third series of alien-busting adventures on CBBC from September. Elisabeth Sladen, who plays Sarah Jane, said: "When I heard the news that David was going to be joining us I was absolutely over the moon." Russell T Davies, executive producer of the show added: "Viewers thought they may have to wait until November for the next full episode of Doctor Who, but this is an extra special treat. "And it's not just a cameo from David - this is a full on appearance for the Doctor as he and Sarah Jane face their biggest threat ever."
