Rossiter

Mr Rossiter was a member of the Vinvocci, an alien race that invented the Immortality Gate. He had been sent to Earth to retrieve the Gate along with Addams. They used Shimmers as disguises in order to blend in with the humans. Rossiter found out that Joshua Naismith, a rich business man, had acquired the Gate after the fall of Torchwood, in order to provide his daughter with immortality. When the Doctor infiltrated Naismith's mansion, the Vinocci's cover was compromised, via the Doctor's sonic screwdriver. (DW: The End of Time)