Susan was the Doctor’s granddaughter and had origins shrouded in mystery. Having escaped Gallifrey with the Doctor, she eventually came to love living an ordinary life as a school girl at Coal Hill School in 1963, where her unearthly demeanour and eccentric knowledge piqued the interest of two of her teachers. This lead to the Doctor having to whisk Susan and the two teachers, Ian and Barbara, back off into time and space.