Addams

Addams was a member of the Vinvocci the alien race that had invented the Immortality Gate. She had been sent to Earth to retrieve the gate along with Rossiter (possibly her husband). They used Shimmers so that the humans would not catch them. Addams found out that Joshua Naismith a rich bussiness man had retrieved the gate opf Torchwood a secret British institue dedicated to defending Earth from aliens. He wanted to use it to make his daugter live for ever. They infultrated his house. But when they wet down to the basement where they had set up base, the where found out by the Doctor and Wilfred Mott who the Doctor was travelling with. There she told the Doctor about the gate. (DW: The End of Time)