"Carole E. Barrowman: The one thing that will send John over the edge, even in public, is if he sees someone being rude or mean or just being disrespectful to an elderly person. Definitely this relationship [with his grandmother Murn] has been a defining one, I think, in his life. […] You cannot underestimate how big a fan of Doctor Who John was when he got that part. He heard about it in Covent Garden when he was with my daughter Claire and he literally ran up a wall."