Ghosts of the Northern Line ( comic story ) Ghosts of the Northern Line was a comic story published in " Doctor Who Magazine " . It was written by Dan McDaid . Summary . In the London Underground people have been going missing since the 19th century . While the Doctor and Majenta Pryce go to see the play , they find the Underground filled with ghosts from different Earth eras . Plot . Part 1 . A man is sweeping up a train when a ghostly girl suddenly appears in front of him . He gets the shock of his life when hundreds of ghosts fly in and advance towards him . The next day the Doctor and Majenta Pryce are on a train in the London Underground to their way to see " The Mousetrap " when the train stops . The Doctor ' s sonic screwdriver picks up a psychic pulse from somewhere down a tunnel . They leave the train , leaving some of the passengers worried by the Doctor ' s talk of " aliens " . As they walk down the tunnel , they find the cleaner who had been taken by the ghosts . He is now a ghost himself . He attacks the Doctor . Majenta picks up the screwdriver and zaps the man . He turns back to his normal self but is still a ghost . His name is Eddie Lang . the Doctor tries to tell him he is dead , but Majenta just blurts it out . He starts ranting on about a machine and then runs off . On the Northern Line a train starts speeding down , when suddenly the same ghostly girl appears . The train stops just in time ; the driver speaks on his phone but he is cut off . While searching for the man , the Doctor tells Majenta that there is no such thing as ghosts . He says they are time leaks and psychic imprints . The Doctor opens a gate and they find " ghosts " of all eras . They ignore them and continue following the psychic pulse . The Doctor says it is just him and Majenta in the tunnels . Then a voice booms , " And me " . The passengers on the stopped train talk to the girl , who says " Look , look up . " Ghostly figures advance on them and she starts to laugh . The Doctor and Majenta find a cybernetic woman in the tunnels who knows their names . She has read their minds . Her name is Mnemosyne and she says all the people , including the Doctor and Majenta , are part of her now . The ghosts begin advancing on them . Part 2 . Twenty minutes before the previous event , the staff at underground control are miffed at the trains stopping . An employee says to his boss , Brian , that he is not sure why . Two minutes later Mnemosyne has the " ghosts " restrain the Doctor and Majenta . Mnemosyne tells the story of how she got to planet Earth , a hundred and seven years ago . Her master , an alien , stole a Mnemosyne unit and sold the technology across the galaxy . He was successful until he came to Earth where the humans battered him to death . Mnemosyne hid in the London Underground , recording psychic patterns of her master . She proceeds to the next step in her plan . She takes over television screens and broadcasts her message , saying she will destroy Earth . Majenta does not understand why , but the Doctor says it is because Mnemosyne wants revenge ; she is programmed to mourn the dead , and she fell in love with her master . The Doctor runs off to stall them , asking Majenta to negotiate with them . The Doctor looks for the junction box and finds a train . He sees that everyone there has been turned into ghosts . He finds the ghostly girl , who turns out to be Mnemosyne in another form . The Doctor refuses to give himself up and runs , only to have the ghosts chase him . Majenta negotiates with Mnemsyne . The " ghosts " tell her to shut up , but the " ghost " of Eddie tells them to hear her out . The " ghosts " say that they are fed up with being lonely . Eddie agrees to help Majenta if she will care for them when they are gone and she promises to do so . The Doctor finds the junction box , but the girl finds him and he is grabbed by the ghosts . They hold him , ready for him to get hit by a train . Eddie confronts Mnemosyne , but she says he should obey her . He hits her on the head with his brush and the " ghosts " attack her . She falls to the floor and begs Majenta to save her , but Majenta smashes Mnemosyne ' s head and the " ghosts " begin to fade away . The Doctor yanks the cables out just in time and the train does not hit him . Meanwhile at Underground control , Brian says that UNIT clearance will clear away the mess . He says on f the phone that the crisis is over . The girl , who has not faded away , says : " Is it Doctor ? Just remember what I said . When the time comes I ' ll be waiting . . . . . . We ' ll all be waiting " As the Doctor and Majenta leaves , Majenta suggests they go and see " The Mousetrap . " The Doctor says no , he is going to Panacea right now . He tells her it is over . A voice comes from the sky , saying it is the voice of Justice , and Intersol has this world completely surrounded . They demand that she come out with her hands up .