▁and ▁is ▁reason ably ▁new ▁to ▁the ▁profession ▁having ▁spent ▁a ▁number ▁of ▁years ▁in ▁the ▁past ▁serving ▁with ▁the ▁British ▁Army . ▁A ▁dark ▁past ▁is ▁hint ed ▁at ▁when ▁he ▁avoid s ▁answering ▁a ▁question ▁from ▁one ▁of ▁his ▁students ▁on ▁whether ▁he ▁has ▁ever ▁killed ▁someone ▁who ▁wasn ' t ▁a ▁soldier , ▁with ▁a ▁te ar ▁rolling ▁down ▁his ▁che ek . ▁He ▁is ▁instantly ▁attract ed ▁to ▁his ▁new ▁colle ague , ▁Clara ▁O sw ald ▁( J en na ▁Cole man ), ▁an ▁English ▁teacher ▁at ▁the ▁school , ▁and ▁attempts ▁to ▁ask ▁her ▁out ▁on ▁a ▁date , ▁which ▁is ▁at ▁first ▁dis astr ous , ▁but ▁she ▁eventually ▁asks ▁him ▁herself . ▁ ▁Their ▁first ▁date ▁is ▁seen ▁in ▁the ▁fourth ▁episode ▁of ▁the ▁series , ▁" List en ". ▁Clara ▁is ▁off ended ▁when ▁D anny ▁pres umes ▁that ▁she ▁will ▁not ▁understand ▁his ▁career ▁in ▁the ▁Army , ▁knowing ▁that ▁she ▁is ▁anti - war , ▁and ▁she ▁storm s ▁out . ▁At ▁the ▁same ▁time , ▁the ▁Doctor ▁( Peter ▁Cap ald i ) ▁is ▁attempting ▁to ▁explore ▁the ▁possibility ▁that ▁everyone ▁has ▁a ▁constant ▁companion , ▁like ▁a ▁shadow , ▁that ▁is ▁always ▁with ▁them , ▁rel ating ▁back ▁to ▁the ▁rec urr ing ▁dream ▁of ▁the ▁mon ster ▁under ▁the ▁bed . ▁W ant ing ▁to ▁explore ▁Clara ' s ▁past ▁experience ▁of ▁the ▁dream , ▁the ▁T ARD IS ▁t aps ▁into ▁her ▁mind ▁to ▁return ▁to ▁her ▁child