 This episode marks the return of Jenna @-@ Louise Coleman , who previously appeared in the series opener , " Asylum of the Daleks " . Coleman was cast because of her chemistry with Matt Smith , and especially because she was able to talk faster than him . She auditioned for the role of Clara , not Oswin from " Asylum " , as the concept of the two characters being the same only occurred to Moffat whilst casting for Clara . The production team requested that the press and fans who attended advanced screenings keep Coleman 's appearance a secret until " Asylum " was broadcast ; the effort was ultimately successful . Moffat stated that the introduction of a new companion made " the show feel different " and brought the story to " a new beginning " with a different person meeting the Doctor . Smith said that Clara was different from her predecessor Amy Pond ( Karen Gillan ) , which allowed the audience to see a different side of the Doctor . Coleman described her as resourceful and not intimidated , citing the reason for following the Doctor at the beginning as pursuing answers . The Clara who would become a travelling companion of the Doctor would not debut until the Spring premiere , " The Bells of Saint John " ; save for a brief cameo at the end of " The Snowmen " . Coleman stated that she played each version as individuals with " trust that there would be a payoff " to her mystery . 
 This episode <a href='uninflect' title='1'><mark>marks</mark></a> the return of Jenna @-@ Louise Coleman , <a href='null_relcl' title='2'><mark>who</mark></a>previously appeared in the series opener , " Asylum of the Daleks " . Coleman was cast because of her chemistry with Matt Smith , and especially because she was able to talk faster than him . She auditioned for the role of Clara , not Oswin from " Asylum " , as the concept of the two characters being the same only occurred to Moffat whilst casting for Clara . The production team requested that the press and fans <a href='null_relcl' title='3'><mark>who</mark></a>attended advanced screenings keep Coleman <a href='null_genetive' title='4'><mark>'s</mark></a>appearance a secret until " Asylum " was broadcast ; the effort was ultimately successful . Moffat stated that the introduction of a new companion made " the show feel different " and brought the story to " a new beginning " with a different person meeting the Doctor . Smith said that Clara was different from her predecessor Amy Pond ( Karen Gillan ) , which allowed the audience to see a different side of the Doctor . Coleman described her as resourceful and not intimidated , citing the reason for following the Doctor at the beginning as pursuing answers . The Clara <a href='null_relcl' title='5'><mark>who</mark></a>would become a travelling companion of the Doctor would not debut until <a href='None' title='6'><mark>the</mark></a>Spring <a href='negative_concord' title='7'><mark>premiere</mark></a> , " The Bells of Saint John " ; save for a brief cameo at the end of " The Snowmen " . Coleman stated that she played each version as individuals with " trust that <a href='dey_it' title='8'><mark>there</mark></a> would be a payoff " to her mystery . 
This episode mark the return of Jenna @-@ Louise Coleman , previously appeared in the series opener , " Asylum of the Daleks " . Coleman was cast cuz of her chemistry w Matt Smith , and especially because she was able to tlk faster den him . She auditioned for da role of Clara , not Oswin from " Asylum " , as the concept of the two characters being tdasame only occurred to Moffat whilst casting for Clara . The production team requested dat thdaress and fans attended advanced screenings keep Coleman  appearance a secret till " Asylum " was broadcast ; the effort was ultimately successful . Moffat stated that the introduction of a new companion made " the show feel diff " and brought the story to " a new beginning " witw/diffediffon meeting the Doctor . Smith said that Clara was different from her predecessor Amy Pond ( Karen Gillan ) , which allowed the audience to see a different side of thedactor . Coleman described her as resourceful and not intimidated , citing the reason fa following the Doctor at the beginning as pursuing answers . The Clara would become a travelling companion of the Doctor would not debut utilSpring no premiere , " The Bells of Saint John " ; save ffaa brief cameo at the end of " The Snowmen " . Coleman stated that she played each version as individuals with " trust that it would be a payoff " to her mystery .