Sarah Jane Smith, portrayed by Elisabeth Sladen, was a companion of the third and fourth Doctors. Sarah Jane was known for feminism and strong affection with the Doctor, who called her his best friend.
Sarah Jane Smith was a perfect foil for the Doctor. Brave, clever, feisty and funny, she was also able to gently poke fun at the Time Lord, even teasing him that after living for 750 years he’d soon be middle-aged! But she remained one of his most resolute and loyal companions.
Resourceful Metropolitan journalist Sarah Jane Smith met the Doctor while posing as her virologist aunt, in an attempt to infiltrate UNIT’s security. Stowing away in the TARDIS, she quickly found herself in mediaeval England.
Sarah’s curiosity, and her feminist views, frequently got her into trouble, but she relished her adventures with the Doctor. She witnessed the Doctor’s regeneration into his fourth incarnation, and continued to travel with him until a call from the Time Lord’s home planet forced him to return her to Earth.
Later the Doctor sent her a present: a robot dog named K9.