Maisie Pitt Maisie Pitt was a passenger aboard the Orient Express . She was the granddaughter of Mrs Pitt , who preferred that Maisie call her " Mum " . Maisie did not like her grandmother . She suspected that Mrs Pitt had poison ed her pony and the Twelfth Doctor later confirmed this . While dining aboard the Express , Mrs Pitt complained to Maisie about a man dressed as a mummy . As she , and others in the carriage , were unable to see it , Maisie took it for illness and encouraged her to take medication . However , the elderly lady was killed by the being , a mythological mummy called the Foretold , with the cause being diagnosed as a heart attack . Having often , half - heartedly , imagined the death of her grandmother , Maisie felt responsible for her passing . In a distressed state , she accused the Twelfth Doctor of lying when he claimed to have visited Thedion Four , as it had been destroyed thousands of years earlier . Captain Quell led her away , telling the Doctor and Clara Oswald that she was distressed following the death of Mrs Pitt . During the night , Maisie attempted to gain access to the baggage train , where the body of her grandmother was being kept . She used a high - heel shoe to bypass security , breaking the electronic system that opened it to do so . With Clara , Maisie went into the baggage train , only to find the body absent . They then became locked in by Gus , the train ' s controlling computer . As they were imprisoned together in the baggage car , Maisie and Clara spent the night talking . They discussed not only Maisie ' s relationship with her difficult grandmother , but also Clara ' s recently challenging relationship with the Doctor . Maisie agreed with Clara that the Doctor had been wrong in his recent actions toward her , but suggested that Clara still cared about him . Following the death of Quell at the hands of the Foretold , Maisie became its next target , selected due to her mental breakdown in the wake of her bereavement . The Doctor had Clara convince her to come to the laboratory . In order to prevent Gus from knowing his true intentions and potentially interfering , he lied to Clara , telling her he had no intention of saving Maisie , and simply needed to observe the details of how the Foretold killed her . He told Clara to lie to Maisie if she needed to do so . Clara reluctantly cooperated , and told Maisie that the Doctor thought he could save her . Released by the computer , she made her way with Clara to the lab , where the Foretold appeared to her . The Doctor used a medical instrument to take her grief , torment and resentment , and imbued his own mind with it . The Foretold disappeared from Maisie ' s view and appeared to him . Now able to access parts of her memory , the Doctor told her that her grandmother had indeed poisoned her pony and expressed sympathy for her father ' s nature . The Doctor identified the Foretold as a soldier and surrendered to it , releasing it to die . Gus then began removing the oxygen from the laboratory , causing the passengers to pass out while the Doctor worked to modify the teleport which the Foretold had been using . Clara woke up to find herself and the Doctor on a beach . He explained that he had saved the remaining passengers , including Maisie , by teleport ing them to the TARDIS , and then dropping them off at the nearest populated world . ( TV : " Mummy on the Orient Express " )