Theo Possible Theo Possible was a time travel ling adventurer and DJ . He was a black man of indeterminable age who dressed entirely in white . He had braid ed silvery hair and a goatee . Theo ' s white suit s were made by S . Stratton . ( PROSE : " Party Kill Accelerator ! " ) He wasn ' t human . ( PROSE : " Happily Ever After Is a High - Risk Strategy " ) History . Theo trained with the Venusians to become an Ascended Master of Klatch - Ki . ( PROSE : " Party Kill Accelerator ! " ) While having adventures in time and space , Theo had numerous encounters with Obsèque Bleak which ended when Theo killed Bleak . Theo travelled with Steve for some time , but that ended when Steve was disintegrated by an Asymmetry Fiend . Theo eventually semi - retired from the adventuring life . ( PROSE : " Happily Ever After Is a High - Risk Strategy " ) Theo held a party in the Zona Obscura for all the ideas which had become " lost in the ether " . Theo was the festival ' s DJ ; as a " sort of cultural exchange " Kelsey from Faction Paradox held his records . For a while , Theo gave the ideas an eternal celebration , but it all came to a stop when Jimmy the Mandrill invited Iris Wildthyme and Panda and their presence instigated a narrative . Theo had to work with Iris to try to stop Jimmy from consuming all the guests at the party . Kelsey finally killed Jimmy , but some of the DJ equipment was damaged in the process , meaning the party could not continue . Theo left the Zona Obscura in a London Underground train after giving Kelsey his record box . ( PROSE : " Party Kill Accelerator ! " ) Theo DJed at the after party for the coronation of Salvinder Heat - Death in the City of the Saved . On another occasion , Theo was invited to the City of the Saved by his old companion Steve to attend Steve ' s engagement party in the Achaean District . Steve had invited Theo because the woman to whom he was engaged was Helénē of Troy and they needed help getting away from all the Greek s and Trojan s that also wanted Helénē . Theo helped Steve and Helénē escape in a U - boat and he was left with a pedalo as his escape vehicle . Theo pedalled for his life and managed to escape to a major road in the nick of time . Theo hitchhiked in Cranzfraction and rested for the first portion of the journey back to the Uptime Gate . Theo woke up while Cranzfraction was telling his life story to Terrence Moody and recognised the name " Litany Chromehurst " , but couldn ' t place it . Theo then told Cranzfraction and Terrence the story of his recent adventure with Steve and Helénē . After arriving at the Uptime Gate , Theo treated Terrence to a meal at Lucrezia ' s Diner . Theo introduced Helénē to Terrence , ( PROSE : " Happily Ever After Is a High - Risk Strategy " ) instigating a relationship which would result in the two marrying . ( PROSE : " Apocalypse Day " ) Behind the scenes . Theo Possible appears in the " Señor 105 " novella " By the Time I Get to Venus " , which also features Señor 105 , El Jefe , Litany Chromehurst , and the Venusians from the First Doctor novel " Venusian Lullaby " . Blair Bidmead , the creator of Theo Possible , has made a webcomic for the character called " Entirely Possible " . Theo also appears in Bidmead ' s short story " Significant Others " from the Obverse Books charity anthology " " . The story features Rose Tyler travelling with Possible after the events of " Journey ' s End " .