Empty Child The Empty Child " plague " was a technological plague which spread around a part of London in 1941 . The Ninth Doctor and Rose Tyler encountered the Empty Child and helped play a part in its cure . History . When conman Captain Jack Harkness planted a Chula ambulance in 1941 London , the Chula nanogene s , who had never previously encountered human s , infected a dying human boy named Jamie caught in the London Blitz . Assuming that the gas mask he was wearing was part of his face , they " healed " him , and unintentionally created the " Empty Child , " a " zombie " based on Jamie ' s characteristics and injuries at death . Thus , everyone affected by the plague inherited a gas mask in place of their faces , severe head trauma on the left side , partial collapse of the chest cavity of the right , and a gash on the back of their right hands . The nanogenes also gave the child the standard abilities of Chula soldiers , specifically super - human strength , telepathic abilities and the ability to communicate using anything with a speaker grill . The Empty Child still had a child - like mentality and escaped to search for its mother . The Empty Child compulsively searched for his mother , and , in doing so , contaminated other human s with the nanogenes . Those who were infected did likewise so that the nanogenes spread in a fashion similar to a virus . The child , and all victims of it , were infamous for repeating the phrase , " Are you my Mummy ? " , endlessly . At first , people were only infected if touched by someone who was already infected , though it soon became airborne . The Empty Child plague was finally stopped when the Ninth Doctor reunited the Empty Child with his mother and the nanogene s understood , recognising the mother as the superior source , the proper sequence for a human of that era . Jamie was fully restored by the nanogenes and the Doctor sent the reprogramed nanogenes to the other infected humans . Now knowing what a proper human was supposed to look like the nanogenes restored the people back to their original selves and repaired all of their injuries and aliments in the process . The Doctor would later state to Rose Tyler that he programed the nanogenes to shut themselves down once they repaired the damage they created to stop them from being a problem again in the future . ( TV : " The Empty Child " , " The Doctor Dances " ) Shortly afterwards , Jamie ' s gasmask was collected and stored in the Leamington Spa Lifeboat Museum . It still contained traces of nanogenes in 2007 . ( GAME : " Security Bot " ) References . The Tenth Doctor , after having assumed the identity of John Smith , drew a picture of two Empty Child victims in " A Journal of Impossible Things " . ( TV : " Human Nature " ) When later given a gas mask during Sontaran invasion of Earth , the Tenth Doctor jokingly asked , " Are you my mummy ? , " as a reference to these events . ( TV : " The Poison Sky " ) When confronted with the Foretold , a mummy on the Orient Express in space , the Twelfth Doctor attempting to find out how and why the mummy was present , blurted out , " Are you my mummy ? " . ( TV : " Mummy on the Orient Express " ) Rose Tyler mentioned having seen " Gas Mask Zombies " when competing with Sarah Jane Smith over their adventures with the Doctor . ( TV : " School Reunion " ) Behind the scenes . Victims of the Empty Child " plague " under the name " Gas Mask Zombies " are used as enemies in the " Doctor Who : Legacy " mobile game .