Magpie owned Magpie Electricals, a business which sold cheap TV sets to Londoners, claiming that it was his "patriotic duty" to allow as many as possible to see Queen Elizabeth II's coronation. In reality, Magpie was hagridden by the alien criminal the Wire, who fed off the energy of humans, leaving them without faces.
Around that same time, the Tenth Doctor and Rose Tyler were passing through, the latter quickly realising that he must be involved because the only new thing in the houses of those attacked were his televisions. When she visited his shop one night, Magpie attempted to get her out before the Wire noticed her, but Rose insisted he come clean. Admitting that he knew he would get found out, Magpie told her that all he wanted was peace from her, pointing to the Wire, who shortly afterwards took Rose's face, Magpie merely watching on with guilt. Magpie promptly dumped her onto the street.
Sparking the fury of the Doctor, who forced his way in the following day with Detective Inspector Bishop and Tommy Connolly, Magpie fled to Alexandra Palace to finish the Wire's plan. Once the deed was done, he told her that all he ever wanted was peace; she responded by saying he'll have it, and killed him by striking him with electricity until he was disintegrated. (TV: The Idiot's Lantern)