Melody Pond
Template:Pre-broadcast spoiler
River Song is a human Archeologist from the far future. (DW: Silence in the Library). She has a sonic screwdriver which is similar in appearance to The Master. She tells The Doctor that he gave her the screwdriver, which he says is impossible. River Song also carries a blue book with her, that she does not let the Doctor read, due to 'Spoilers'. It is very TARDIS like. River also talked about past times with the Doctor, but that will be in the Doctor's future.
Behind the Scenes
River Song is due to make an appearance in Silence in the Library and its second part Forest of the Dead. Tabloids have published that she is a Time Lady but this is unlikely as Russel T. Davies would not allow another writer such an important storyline and it would not be revealed so soon in the series.