Cathy Salt was a journalist who worked as the science corespondent for the Cardiff Gazette.
In 2006, she investigated the new nuclear power station and came across Mr Cleaver's internet page. This page told her the plant was not safe — indeed, it would destroy the whole of Cardiff. Subsequently, she went to a press conference held by the Lord Mayor, Margaret Blaine. When she pressed Blaine for an explanation for all the deaths associated with construction of the plant, the Lord Mayor claimed they were all accidental. Blaine took Cathy aside for a private interview in the ladies' toilet. In the privacy of her stall, the Lord Mayor removed her skin suit to reveal she was a Slitheen. She planned to kill Cathy, but when Cathy revealed she was pregnant, "Margaret" was moved to spare her life. (TV: Boom Town)