▁plot , ▁and ▁the ▁impact ▁of ▁the ▁un for ese en ▁ending . ▁ ▁Production ▁The ▁second ▁series ▁of ▁Inside ▁No . ▁ 9 ▁was ▁written ▁in ▁ 2 0 1 4 , ▁and ▁then ▁fil med ▁from ▁the ▁end ▁of ▁ 2 0 1 4 ▁into ▁early ▁ 2 0 1 5 . ▁" The ▁ 1 2 ▁Days ▁of ▁Christ ine " ▁follows ▁the ▁life ▁of ▁Christ ine ▁over ▁ 1 2 ▁years , ▁with ▁the ▁story ▁told ▁through ▁scenes ▁showing ▁the ▁key ▁events ▁in ▁that ▁time . ▁She ars m ith ▁described ▁this ▁as ▁a ▁very ▁unusual ▁episode ▁structure ▁and ▁story t elling ▁method , ▁but ▁felt ▁that , ▁in ▁this ▁case , ▁it ▁was ▁effective . ▁On ▁writing ▁the ▁script , ▁P ember ton ▁and ▁She ars m ith ▁immediately ▁thought ▁of ▁Sher idan ▁Smith ▁as ▁a ▁perform er ▁who ▁would ▁be ▁suitable ▁to ▁play ▁Christ ine . ▁Both ▁had ▁previously ▁worked ▁with ▁her , ▁and ▁the ▁pair ▁hoped ▁that ▁she ▁would ▁be ▁willing ▁to ▁accept ▁the ▁role . ▁Smith ▁had ▁been ▁a ▁long - time ▁fan ▁of ▁the ▁writers ' ▁work , ▁and ▁enjoyed ▁the ▁way ▁the ▁format ▁of ▁Inside ▁No . ▁ 9 ▁allows ▁stand alone ▁stories . ▁She ▁was ▁" g ri pped " ▁by ▁the ▁script , ▁and ▁accepted ▁the ▁role ; ▁during ▁film ing , ▁she ▁said ▁she ▁was ▁" over ▁the ▁moon " ▁to ▁be ▁working ▁with ▁P ember ton ▁and ▁She ars m ith . ▁ ▁As ▁each ▁episode ▁of ▁Inside ▁No