 Adam Mitchell joins the Doctor and Rose in the episode "Dalek". The character was first conceived during Russell T Davies'2003 pitch to the BBC: it was always the intention for Adam to join the TARDIS team after Rose developed a liking for him. Contrasting against Rose, Adam was created to show that not everybody is suited to be a companion. Davies stated that he "always wanted to do a show with someone who was a rubbish companion" and dubbed Adam "the companion that couldn't". Upon returning Adam home, the Doctor informs him that "I only take the best. I 've got Rose". Fraser McAlpine, reviewing Adam's appearances as companion for BBC America's Anglophenia blog, described Adam as fulfilling a role as "the companion that proves the worth of all of the other companions". From episodes nine through thirteen, Rose and the Doctor are joined by the con man Jack Harkness. Jack's appearances were conceived with the intention of forming a character arc in which Jack is transformed from a coward to a hero. John Barrowman, reflecting on the interrelationships between The Doctor, Jack and Rose, felt that "the subtle sexual chemistry between all three characters ... was always in play" with the caveat that "the relationships were by no means driven by desire". SFX magazine also commented on the "intoxicatingly flirtatious dynamic" and compared the trio to "a Buffy-style Scooby gang who can quip in the face of danger". Jack parts from the Ninth Doctor with a kiss which Barrowman felt to be "full of fondess and respect" and both "a significant moment in the annals of the series" and "a moment full of melancholy and loss for the characters".
