Molly O ' Sullivan Mary " Molly " O ' Sullivan , later Mary Carter , was an Irish Voluntary Aid Detachment nursing assistant who was stationed in France during World War I . When the Eighth Doctor regenerated , Molly was the last companion that he remembered . Biography . Childhood . Molly was born in 1891 as the daughter of Patrick and Cathy O ' Sullivan ( AUDIO : " Tangled Web " ) and had seven siblings , all of whom she outlived . ( AUDIO : " Fugitives " , " X and the Daleks " ) Two of her brothers and her three sisters died before their fifth birthdays . She had two other brothers , Patrick and Liam . Patrick joined the British Army in World War I and was killed on his first day in France while Liam remained in Ireland but was killed by an English sentry . ( AUDIO : " X and the Daleks " ) On her second birthday , Molly became " lost in a storm " , and fell into the clutches of Kotris . Kotris took Molly to his TARDIS and infused her with retro - genitor particle s , then returned her home to her parents . ( AUDIO : " Tangled Web " ) The effect of the retro - genitor particles gave Molly unusually dark eyes . She was teased for her dark eyes when she was a child and when she first entered domestic service . However , this teasing ended when she began to punch the people who mocked her . ( AUDIO : " X and the Daleks " ) Meeting the Doctor . Before the outbreak of World War I , she worked as a chambermaid for the Donaldson family in Eaton Place in London . She became friends with the Donaldsons ' daughter Kitty , who viewed her as being the sister that she never had . When Kitty became a VAD in France , Molly did likewise as she knew that her mistress needed someone to protect her . After several months serving in France , Kitty contracted an infection from one of the soldiers whom she was treating . She was eventually killed by the renegade Time Lord Kotris and the Dalek s . Molly met the Eighth Doctor in France , with whom she began to travel after they were chased across No Man ' s Land by the Daleks . ( AUDIO : " The Great War " ) The first place the Doctor took Molly was Dunkirk in 1941 . They were not there long before the Daleks appeared once more , chasing them across the town . They were also chased to London in 1972 , and the planet Halalka . ( AUDIO : " Fugitives " ) Shortly after leaving Halalka , Molly and the Doctor seemingly arrived on Skaro , where they discovered that the Daleks had become peaceful , after they caused the extinction of the Time Lords . However , it was later revealed that this was a simulation generated on their behalf . ( AUDIO : " Tangled Web " ) The Doctor and Molly were directed to Srangor by the Time Lords , where Molly discovered that she had been implanted with retro - genitor particles . The effects of this were erased when Straxus — a younger version of Kotris — was killed , thus erasing Kotris and everything he accomplished from history . She departed the TARDIS after it materialise d in France during World War I . Molly realised that with Kotris having been erased from history , Kitty would still be alive and that she had to continue taking care of her as she promised . ( AUDIO : " X and the Daleks " ) Molly returned to London and stayed at 107 Baker Street . In 1918 she met the Doctor again , and had an encounter with the Viyran s . ( AUDIO : " The White Room " ) The Doctor and Molly travelled to the " Orpheus " , where Molly met Liv Chenka for the first time . Shortly after , the ship came under attack by the Eminence , and it began to possess the crew . After defeating the Eminence , Molly and the Doctor were joined on their travels by Liv . ( AUDIO : " Time ' s Horizon " ) Molly , Liv and the Doctor ' s next stop was London in the 1970s , where Molly helped the Doctor to defeat and the Eminence . After they were defeated , Molly stayed behind in 107 Baker Street and awaited the Doctor ' s return from Nixyce VII . One night she heard a knock at the door , and was kidnapped by Sally Armstrong and the Master . ( AUDIO : " Eyes of the Master " ) The Master edited Molly ' s memories , replacing the Doctor with the Master , creating a sense of trust between them . ( AUDIO : " Rule of the Eminence " ) The Master took Molly to Heron ' s World , where she became part of the Master ' s experiment to pass some of her retro - genitor particles onto other humans . ( AUDIO : " The Death of Hope " ) The Master place her in her initial teleportation capsule hoping that he could the Eminence under his control . ( AUDIO : " Masterplan " ) The Master used her to create the grand administrator Walter Vincent based on her father . Her singing annoyed the Master . Molly parted company from the Doctor after it was deemed she would be unsafe travelling with him , they parted ways as she was to be returned to her proper place in time by Narvin . ( AUDIO : " Rule of the Eminence " ) In the new Dalek timeline , she was in Moscow in 1961 where she was known as " Mary Carter " . Rastel ordered her to look after the Eighth Doctor . She didn ' t recognise him at first , but this was a deception . The Master wanted her to stabilise the timeline . She knew that something was wrong with time when the Daleks invaded Earth as she had known the future . ( AUDIO : " Master of the Daleks " ) After the Dalek Time Controller took Liv and Molly to the Eye of Orion , she started to become ill . When the Doctor met up with her she started to feel better , and wanted the Doctor to stop the Daleks . She also tried to stop Anya . Her eyes turned dark for the last time , which allowed her to control the TARDIS . Because of the retro - genitor particle she was still linked with the Time Controller if either of them died they would both die . She sacrificed her own life so that the Time Controller could die , and she became part of the Eminence . She used the Time Controller ' s link with the Time Vortex and sent the Eminence to the end of the universe . ( AUDIO : " Eye of Darkness " ) Legacy . When the Eighth Doctor was about to regenerate , he remembered Molly last among his past companions . ( TV : " The Night of the Doctor " ) The Twelfth Doctor saw Molly , among other companions , when Bernice Summerfield was hit by temporal energy in the Pyramid Eternia . ( PROSE : " Big Bang Generation " ) Behind the scenes . Molly is the first Irish companion that the Doctor has had in any medium .