Izzy Sinclair Isabelle " Izzy " Sinclair was a human companion of the Eighth Doctor . Orphaned at a young age , Izzy spent several of her developing years unsure of who she was or who she wanted to be . While her early years were light and uneventful , her teens brought a great distrust towards the authority figures in her life . Izzy left Earth without telling her adoptive parents , as she was trying to escape what she felt was a too - mundane life . ( COMIC : " The Glorious Dead " ) She revelled in travel with the Doctor , even though it was often dangerous . However , her vivacious and trusting nature eventually had tragic consequences . ( COMIC : " Ophidius " ) Biography . Early life . Izzy was born on 12 October 1979 , ( COMIC : " TV Action ! " ) and was left at a bus shelter by her biological parents a few hours after being born . ( COMIC : " The Glorious Dead " ) She was later adopted by Les and Sandra Sinclair . ( COMIC : " Endgame " ) At the age of eight , Izzy was told that she was adopted . The truth hurt Izzy , and she began to tell herself that she was a lost alien princess , and someday her alien parents would find her . ( COMIC : " The Glorious Dead " ) Because of her unknown ancestry , she chose to call herself Izzy S ( for " Izzy Somebody " ) from then on . ( COMIC : " Endgame " ) Travels with the Doctor . When she first met the Eighth Doctor , Izzy was a seventeen - year - old science fiction fan and amateur paranormal investigator . She lived in the town of Stockbridge , England . She was a friend of Maxwell Edison . She met the Doctor after Max and she had stolen an artefact being sought by the Doctor ' s old enemy , the Celestial Toymaker . The Toymaker had put the entire town of Stockbridge into a pocket dimension and turned everyone into dolls save for Izzy and Max . The Doctor arrived in the midst of this , rescued the town , defeated the Toymaker again and took Izzy on board the TARDIS as his newest companion . ( COMIC : " Endgame " ) The Doctor once took Izzy to Jora , where all native life forms were affected by the Syntax . Izzy fell under its influence , and saw Jean - Luc Picard whilst hallucinating . ( PROSE : " Syntax " ) Izzy helped the Doctor to discover the mystery behind the disappearance of the 56th issue of " Aggrotron ! " , one of her favourite comics whilst she was growing up . ( AUDIO : " Izzy ' s Story " ) The Doctor swapped the Crystal of Consciousness with an identical duplicate , which Valis stole . Valis restrained the Doctor and Izzy , having them at his mercy , when the fake crystal backfired on him upon it being placed in Valis ' psychic web . Izzy mocked this substitution as obvious . ( COMIC : " Death to the Doctor " ) Losing her body . When the TARDIS was swallowed by a gigantic , snake - like spacecraft called Ophidius , Izzy and the Doctor met Destrii , an amphibious alien who looked like a humanoid fish . Destrii was pursued by the aliens who controlled Ophidius and gained Izzy ' s confidence , only to switch bodies with her to evade capture . When Destrii ( in Izzy ' s body ) was apparently disintegrated , Izzy had to deal with the possibility she would be in an alien body for the rest of her life . Izzy had never learned how to swim before ending up in Destrii ' s body . ( COMIC : " Ophidius " ) Izzy reacted badly to having a new body , lashing out at the Doctor when he tried to help . Shortly after , Izzy began to suffocate as her new body needed to be submerged in water periodically . The Doctor carried Izzy through the TARDIS to the swimming pool , submerging her in the water . Izzy then learnt how to breathe in her new body , and apologised to the Doctor for pushing him away . ( COMIC : " Beautiful Freak " ) Just as she was adjusting to her new body , Izzy was kidnapped by operatives of Destrii ' s mother , the Matriax Scalamanthia of the planet Oblivion , who wanted her " daughter " to prepare for her wedding by fighting a duel to the death . While trying to trace Izzy ' s whereabouts with the help of his former companion Fey , the Doctor discovered that Destrii was still alive and went to Oblivion to switch their bodies back . Destrii and Izzy saw into each other ' s minds . Destrii saw how finding out she had been adopted made Izzy withdraw emotionally , unable to trust herself or admit she was a lesbian . Finally coming to terms with who she was , Izzy asked the Doctor to take her back to Stockbridge so she could make amends to her adoptive parents . The Doctor dropped Izzy off at the moment she began travelling with him . From her parents ' point of view , she had never left . ( COMIC : " Oblivion " ) After the Doctor . Izzy survived the Cyberman invasion of Earth in 2005 . ( COMIC : " The Flood " ) By December 2008 , Izzy had taken to travelling the world . She found " something amazing " in Kabul . ( COMIC : " The Stockbridge Child " ) At some point , she began working for Médecins Sans Frontières : making her a doctor who travelled . ( COMIC : " The Stockbridge Showdown " ) In 2016 , she was going to return to Stockbridge for Max ' s sixtieth birthday when the Twelfth Doctor asked for her help in taking down Josiah W . Dogbolter . Izzy delivered a knockout blow to Dogbolter and watched him get arrested in his own time , before taking a TARDIS trip to Cornucopia for Max ' s birthday party . She caught up with Destrii there . When the Doctor asked if she ' d made up with her parents , she laughed that she was thirty - six now and that issue had been solved years ago . ( COMIC : " The Stockbridge Showdown " ) Legacy . The Tenth Doctor told Gabby Gonzalez about Izzy , along with several other former companions . ( COMIC : " Vortex Butterflies " ) Parallel universes . Lizzy Sinclair was an alternate version of Izzy that was a lizard . She was a companion of Tardis Tails . ( COMIC : " The Glorious Dead " ) Personality . Izzy was brought up watching science fiction on TV and reading books by authors as varied as Iain M . Banks and H . P . Lovecraft . She felt she was ready to travel with the Doctor , but found she was mistaken , and that real life far exceeded fiction in fantastic and terrible ways . During and after the Doctor ' s abduction by the Master , Izzy was left to cope with a morose and to deal with a failing resistance to the Ash Wraith invaders . ( COMIC : " The Glorious Dead " ) Izzy frequently watched " " on VHS before travelling with the Doctor . ( AUDIO : " Izzy ' s Story " ) She had a poster of Darth Vader in her bedroom aboard the Doctor ' s TARDIS . ( COMIC : " Beautiful Freak " ) She was an atheist . ( PROSE : " Syntax " ) After swapping bodies with Destrii , Izzy ' s burgeoning self - confidence was first shaken and then strengthened when she came to terms with the change and the successful return to her body . The ultimate realisation of that growth was when she could tell the Doctor she was ready to go home and kissing Fey , accepting her own homosexuality . ( COMIC : " Ophidius " , " Oblivion " )