A 19-year-old London shop assistant who, in 2005, walked into the TARDIS and brought Doctor Who back to life.
Played by Billie Piper, she was the first companion of the revived series, travelling with the ninth and tenth incarnations of The Doctor. Their goodbye in “Doomsday” (2006) is the great heartbreak of modern Doctor Who: trapped in a parallel world, on a beach, she says she loves him, and the connection is cut before he can answer.
The other love story of the series, the complicated one: River Song.