Mickey Smith was an auto mechanic and resident of the Powell Estate who came to befriend the Doctor, Sarah Jane Smith, Captain Jack Harkness, Jackie Tyler and another world’s Peter Tyler by virtue of his youthful romantic relationship with Rose Tyler. An apparently typical teenager — obsessed with football, sex and alien conspiracy theories — he rose to become a principal defender of not just one but two planet Earths. After years of living with the Tyler family on a parallel Earth, he returned to his “home Earth” and married Martha Jones. Despite close ties to the Torchwood Institutes of two Earths, he and his wife ultimately struck out on their own to become “freelance” alien fighters.
When first seen, Mickey was a bumbling coward; his capture by the Autons and initial trip in the TARDIS left him greatly shaken. (TV: Rose) When he met the Doctor again, he displayed resentment towards him. (TV: Aliens of London) Already, though, he was braver than he had been; he tried to hold off a Slitheen to give Jackie time to escape. (TV: World War Three) Despite these changes, Mickey was still clumsy, performing a pratfall while trying to capture Blon Fel-Fotch Passameer-Day Slitheen. (TV: Boom Town) Although still unwilling to travel in the TARDIS, Mickey changed his mind, inviting himself along, unwilling to just be “technical support” (or the tin dog) any more. (TV: School Reunion)
Mickey reached a turning point when he met Ricky and witnessed his death at the hands of the Cybermen. Shown a version of himself that was braver, he rose to the challenge. (TV: Rise of the Cybermen / The Age of Steel) He played a crucial part in the the Cybermen’s defeat and chose to help rid the alternate Earth of their threat. (TV: The Age of Steel) When the Cybermen found a way to cross over to the other Earth, Mickey was the first to pursue them. (TV: Army of Ghosts) When all of reality was threatened, Mickey again crossed Earths, this time with Jackie in tow. They faced Daleks and Mickey held their creator, Davros, at gunpoint. (TV: Journey’s End) Choosing to return home, Mickey found love with Martha Jones; they became freelance alien hunters. Far from his original cowardly ways, Mickey now actively pursued dangerous aliens. (TV: The End of Time)