text: hide ( doctor who ) " hide " is the ninth episode of the seventh series of the british science - fiction drama doctor who , first broadcast on bbc one on 20 april 2013 . it was written by neil cross and directed by jamie payne . in the episode , alien time traveller the doctor ( matt smith ) and his companion clara oswald ( jenna - louise coleman ) visit a mansion in the 1970s owned by professor alec palmer ( dougray scott ) , which appears to be haunted . palmer 's assistant , emma grayling ( jessica raine ) , is an empath who is able to connect to the ghost . the doctor discovers that the ghost is really a time traveller from the future ( kemi - bo jacobs ) who is trapped in a pocket universe , and he travels there to rescue her . there he discovers a bizarre " crooked man " ( aiden cook ) , who also seeks to escape the pocket universe and be reunited with its mate in the mansion , who had been the source of much of the mysterious activity in the mansion . " hide " was the first contribution to doctor who of writer neil cross , who was a fan of the show but had never had the time to write an episode . cross wanted to write a scary episode and was inspired by nigel kneale 's works the quatermass experiment and the stone tape . the storyline of " hide " was kept to a restricted setting and characters , although it was expanded thematically to flesh out the monster with a love story that paralleled that of professor palmer and emma . the first to be filmed for the second half of the series — predating coleman 's introduction as full - time companion in the christmas special — " hide " began filming in late may 2012 at margam country park , gethin forest , and a national trust property at tyntesfield . the episode was watched by 6 . 61 million viewers in the uk and received generally positive reviews from critics . plot synopsis on a dark and stormy night in november 1974 , professor alec palmer ( dougray scott ) and his assistant emma grayling ( jessica raine ) collect photographic evidence of a ghost in caliburn house . professor palmer is using emma 's strong psychic powers to create a connection that appears to summon the ghost . they are surprised by the arrival of the doctor and clara , who claim to be from military intelligence . the doctor shows interest in the investigation and clara points out that the ghost appears in the same position within each photograph . clara speaks with emma and reassures her that emma 's feelings for professor palmer are reciprocated ; at the same time , emma warns clara about the doctor , sensing " a sliver of ice " in his heart . the doctor and clara find a location in the mansion which is noticeably colder than the rest of the house , and they feel as if they are being watched . suddenly the house grows cold and clara feels something holding her hand when there 's nothing there . the two race back to where the professor and emma are waiting to see palmer 's equipment activating of its own accord . a thin black disc materializes in front of them and emma senses something crying out for help before the disc vanishes and the house returns to normal . the doctor takes clara in the tardis to examine their specific location at various points during earth 's history and repeatedly takes photographs of the same area . clara is dismayed by the doctor 's lack of compassion at witnessing the whole of humanity 's history during these trips , complaining that " we 're all ghosts to you " . she also grumbles that she thinks that the tardis doesn 't like her . from his pictures the doctor comes to the conclusion that the " ghost " is actually a pioneer time traveler named hila . hila was trapped in a pocket dimension where time moves more slowly ; for every second she is trapped in the pocket dimension one hundred thousand years pass in the normal world . the doctor realizes that he cannot use the tardis to rescue her because the entropy of the pocket dimension would drain the tardis of its energy within seconds . instead , the doctor prepares a device which includes a blue crystal from metebelis iii to stimulate emma 's psychic abilities to open a gateway to this pocket dimension . once opened , the doctor will travel across and rescue hila with a harness anchored in the normal world . emma opens the gateway and the doctor travels through where he finds himself on a small island of land floating in a void . he finds hila and they are drawn to a vision of caliburn house that emma has generated for them as a beacon . at the same time , a creature follows them and chases them into the house . the doctor locks the doors to slow the creature down , and hila uses the harness to return to the normal world . the strain of keeping the gateway open causes emma to collapse and the gateway closes , trapping the doctor in the pocket universe . the tardis ' cloister bell begins to sound , and clara races to the tardis to find it locked . she pleads with the device via its holographic voice interface to help her save the doctor , and after initially refusing the tardis finally opens up and allows clara in . as emma reopens the gateway again with palmer 's encouragement , the tardis briefly flies into the pocket universe and moves close to the ground , allowing the doctor to jump and hang on before the creature can grab him . the doctor and the tardis safely reappear in the normal world as emma collapses from the pain and exhaustion . before leaving the next morning , the doctor stops to ask emma if she could sense anything unusual about clara , but emma reveals that clara seems normal to her . the doctor offers hila a lift to any other place in history and concludes that she is a direct descendant of emma and palmer . he reasons that their relation resulted in a blood connection that helped them open the gateway to rescue her . while contemplating the bonds that love can create , the doctor suddenly realises that there is another creature within caliburn house . just as emma and palmer were not part of a ghost story but a love story , the doctor considers the same for the creatures — that the one trapped in the pocket universe has been trying to reunite with its mate . the doctor asks emma for a favour and they use emma and the tardis to retrieve the other creature from the pocket universe . continuity metebelis iii has featured before when the third doctor ( jon pertwee ) took a blue crystal from the planet in the green death and returned it in planet of the spiders , although it was pronounced differently . the doctor mentions the eye of harmony , which was introduced in the deadly assassin . the doctor puts on the orange spacesuit he wore originally in " the impossible planet " / " the satan pit " and wore on a number of occasions up to " the waters of mars " when taking the photos . production writer neil cross was a doctor who fan , but had never had the time to write an episode . executive producer caroline skinner , who was new with the seventh series , knew him and offered to work his schedule around writing an episode ; he was willing to do it . executive producer and lead writer steven moffat was pleased to have cross join , as he was a showrunner in his own right with luther . cross also wrote the seventh episode of the series , " the rings of akhaten " , which he was invited to do after the producers enjoyed " hide " . the script process of " hide " involved no face - to - face meeting , as cross lives in new zealand . however , he flew in with his family to watch the filming . cross wanted to write " a really old - fashioned scary episode of doctor who " targeted especially at children nine to twelve , which was how he remembered doctor who at that age . he stated that " time travel and ghosts are echoes of one another . what is a ghost , if not a fragment caught in time ? " he aimed to show suspense and tension , as he felt it was more terrifying than " full - on shock horror blood and gore " . cross was inspired by the quatermass experiment and its sequels , and originally intended to have the doctor meet bernard quatermass , though this was not possible , for copyright reasons . cross was also inspired by quatermass writer nigel kneale 's the stone tape , which was why he set the story in the 1970s . " hide " was intended to be a " very small , very restricted ghost story " , but he was asked to make it bigger in the end . the different universe was present , but it was " smoke and mirrors " and the climax originally took place in the house , just in daylight and in the alternate world . the idea of the crooked man was something cross said lurked in his imagination . the love story twist was added in later , because moffat felt the monster should be more fleshed out , and cross chose to mirror the love plot between emma and the professor . cross wanted to tell the story with " a small cast and as few locations as possible " . jessica raine was offered the part of emma grayling , and later said that she had not realised " what an institution doctor who is " until she arrived on set . she said it was produced very differently from her series call the midwife . raine had also worked with matt smith before on a play . cross said that raine and co - guest star dougray scott were good at filling out their characters , as he found it difficult to fully " evoke the history of a quite complex relationship " between their characters with just the script . subsequent to filming her appearance in this episode , raine was cast as doctor who 's original producer , verity lambert , in a docudrama made for the show 's 50th anniversary , an adventure in space and time . " hide " was the first episode jenna - louise coleman filmed as clara . cross only had coleman 's five - minute audition for " asylum of the daleks " , in which she played a different but mysteriously linked character to work from , and some editing was done to her lines to make her sound less " bitchy " . otherwise , the scripting process was " smooth " . the read - through for " hide " took place on 21 may 2012 ; filming began three days later , on the 24th . scenes for the mansion were filmed at margam country park in june . tyntesfield , a national trust property near bristol was used as the mansion . the scenes in the forest were filmed in the gethin forest in wales , with artificial mist . the crooked man 's movements were done in reverse and then played forward , to give it an unnatural movement . director jamie payne had cross 's children be " monster consultants " during filming and evaluate if it was scary enough . cultural references the episode also contains several cultural references . clara introduces herself and the doctor as " ghostbusters " , a reference to the film of the same name which would not be made for another nine years from the time at which the episode is set . the doctor recites in his dialogue the lyrics " birds do it , bees do it , even educated fleas do it " from " let 's do it , let 's fall in love " by cole porter as he realises that the crooked man is just a lost lover . the doctor also mentions the baker street , who assisted sherlock holmes in several of arthur conan doyle 's stories . however , the doctor is in fact alluding to the special operations executive , a british world war ii organisation that professor palmer was a part of . broadcast and reception " hide " was first broadcast in the united kingdom on bbc one on 20 april 2013 . overnight ratings showed that the episode was watched by 5 million viewers live . when time - shifted viewers were calculated , the figure rose to 6 . 61 million viewers , making it the sixth most - watched programme of the week on bbc one . in addition , " hide " received 1 . 53 million requests on the online bbc iplayer for april , placing sixth for the month on the service . it also received an appreciation index of 85 . critical reception the episode received generally positive reviews . neela debnath of the independent praised how the episode blended a haunted house story with a science fiction tale , highlighting the twist at the end of " ugly aliens have feelings too " . the guardian 's online reviewer dan martin said that it had " the hallmarks of an episode that will be discussed for years to come " , including the guest stars and atmosphere . he praised the direction , but criticised some of the dialogue . daisy bowie - sall of the daily telegraph gave " hide " four out of five stars . radio times reviewer patrick mulkern gave " hide " a positive review , highlighting smith 's performance and the spookiness . while he praised raine and scott , he felt that hila was " shortchanged " , and also criticised the " love story " ending . the a.v. club 's alasdair wilkins gave the episode an a- , praising the way it changed direction and the subtle hints about the doctor . morgan jeffery of digital spy awarded the story four out of five stars , writing that it flowed better than cross ' last episode , " the rings of akhaten " , and allowed for the exploration of several themes . while he was positive towards the way the story was tied back to a time traveller , he felt that the ending was " perhaps less interesting than what 's come before , simply because it feels more familiar " , though it was still " solid " . ign 's mark snow gave the episode a score of 8 . 4 out of 10 . he praised the smaller scope and focus on character , but wrote " the left - field genre detour didn 't completely convince , and felt jarringly underwhelming considering the spooky set - up , but at least it tried something unique " . jordan farley of sfx gave " hide " four out of five stars . farley felt that the science fiction element left too many answers , but said that it excelled as a love story . in doctor who magazine , graham kibble - white gave " hide " a positive review , describing it as " simply terrific . " he said that it was the first " out - and - out ghost story " in the series , and claimed that fact " wonderful . " also , he described the story as " fascinating in the way it portrays the ghosts of the living , " and said it " transcends neil cross ' other story , the rings of akhaten , and even rises above the unfortunate mispronunciation of metebelis three . "