The 57th ( short story ) The 57th was the fifth short story in the Short Trips anthology " " . It was written by John Binns . It featured the Fifth Doctor and Nyssa . Summary . Sarah Emmins , her husband Stuart Gorey and her research assistant Ian Bird have been working at the fifty - seventh research station on Fraternity . The dangerous chemical storms prevent them from gathering samples except during brief intervals in the storm . One day after Ian returns to the station after collecting samples , he and the other two are surprised to see someone else return to the station , and even more surprised when he takes off his bio - suit to reveal that he is identical to Ian . Sarah and the others quarantine the duplicate and take some samples from him , but they have no idea what he is . He is just as confused as the others . The head station shuts down the project for now and demands answers from the fifty - seventh . Two experts arrive , and the head station orders that Sarah and her team cooperate . When the experts , who introduce themselves as the Doctor and Nyssa , arrive , there are some awkward moments but the Doctor assures them that he and Nyssa have dealt with difficult problems before . He proposes that they interview each of the station members , including the duplicate , separately . They discover that Sarah has accepted the duplicate , Stuart is suspicious that it ' s part of some plot , and Ian believes some of Stuart ' s suggestions . The duplicate is concerned about his rights , as he has been experimented on , and begins to feel he is unique and that he should be an ambassador for whatever intelligent life may be on the planet . Later , as the Doctor , Nyssa and Bird are in the recreation area , they hear an alarm . They find that Stuart has been attacked by the duplicate , who has taken Sarah and has Stuart ' s gun . They deduce that the duplicate has taken her to the collection room , but when they get there , they find he has changed the lock . Nyssa suggests they use the video link to let them see inside the room . Inside the collection room , Sarah is tied to a chair . The duplicate seems to have anticipated that they would monitor him , so the Doctor tries to talk to him via the link . The duplicate makes his demands : he wants to be treated like an ambassador , he wants to be taken to the head station , and he wants to have a say in the project . When the Doctor informs him that they can ' t let him dictate terms , the duplicate shoots the video camera , and they lose the picture . They head for the collection room , afraid that the duplicate will open the outside door , exposing Sarah to the chemical storms . They get the door open , and the Doctor enters , reasoning that he would be able to survive the storms longer than the others . His attempts to placate the duplicate fail , however , and the duplicate opens the doors . He shoots the Doctor , and when Stuart and Ian enter , he shoots Stuart as well . Ian grabs Sarah , chair and all , and takes her from the room . The Doctor , shot in the leg , tries to rescue Stuart , but it ' s too late . He tells the others that he doesn ' t know what happened to the duplicate . On their way back to the TARDIS , the Doctor and Nyssa lament their failure . The Doctor isn ' t consoled to be reminded that he tried his best , because trying his best and failing offends his " sense of optimism " . He promises Nyssa a vacation .