app ell . ▁Car ole ▁Ann ▁Ford ▁as ▁Z or elle , ▁a ▁vain ▁and ▁wealth y ▁fashion ▁designer ▁( although ▁it ▁is ▁suggested ▁by ▁Mari ▁that ▁it ▁is ▁actually ▁her ▁sister ▁that ▁is ▁the ▁bra ins ▁of ▁the ▁company ) ▁who ▁also ▁drink s ▁too ▁much ; ▁she ▁is ▁killed ▁by ▁the ▁R ut an ▁shapes h if ter ▁which ▁later ▁assumes ▁her ▁form ▁at ▁the ▁conclusion ▁of ▁the ▁story . ▁Ford ▁was ▁best ▁known ▁as ▁playing ▁Susan ▁For eman , ▁the ▁grand d augh ter ▁of ▁the ▁Doctor ▁in ▁the ▁original ▁series . ▁Soph ie ▁Ald red ▁as ▁Mari , ▁the ▁f ian c ée ▁of ▁Nik os ; ▁the ▁spo ilt ▁and ▁pam per ed ▁daughter ▁of ▁a ▁planet ary ▁president , ▁she ▁is ▁st unn ed ▁by ▁the ▁S ont ar ans ▁and ▁later ▁killed ▁by ▁the ▁R ut an ▁when ▁it ▁inv ades ▁her ▁qu arters - ▁the ▁R ut an ▁form ▁of ▁Mari ▁then ▁k ills ▁Z or elle . ▁Ald red ▁had ▁previously ▁played ▁A ce , ▁companion ▁to ▁the ▁sevent h ▁Doctor ▁in ▁Doctor ▁Who . ▁Keith ▁Bar n father ▁suggested ▁to ▁Ald red ▁that ▁she ▁take ▁on ▁the ▁role ▁of ▁Lisa ▁Der anne ▁after ▁Elisabeth ▁S lad en ▁dropped ▁out , ▁but ▁she ▁wanted ▁to ▁play ▁a ▁more ▁femin ine ▁character ▁instead ▁after ▁three ▁years ▁of ▁playing ▁A ce ▁in ▁Doctor ▁Who . ▁R ory ▁O ' D onn ell ▁as ▁Nik os , ▁Mari ' s ▁f ian cé ▁and ▁the ▁son ▁of