Rossiter

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