 Elisabeth Sladen previously played Sarah Jane between 1973 and 1976 . In 1981 , she was offered the role again to ease the transition between the Fourth and Fifth Doctors , which she declined , but agreed to star in the pilot ( and only episode ) for the spin @-@ off series K @-@ 9 and Company , which brought her together with K @-@ 9 , another popular character . After her appearance in The Five Doctors in 1983 , she temporarily stopped acting in order to raise her family , but lent her voice to several Big Finish audio productions . She returned to Doctor Who in the aptly titled Tenth Doctor episode , " School Reunion " . Sladen and Tommy Knight have also appeared as Sarah Jane and Luke Smith in the series 4 finale , " The Stolen Earth " / " Journey 's End " , and in the second and final part of David Tennant 's swan song as the Tenth Doctor , The End of Time . 
