Ellen Hunt, MA, codenamed Venessa, was a human who was involved with the 456 in 1965.
Hunt worked as a Civil Service secretary in the 1960s. She informed Jack Harkness of the 456's offer: a cure for a flu epidemic in return for twelve children. She chose Jack to complete the handover as he didn't care for the children. She told Jack that if he didn't exchange the children for a flu antivirus, the flu strain would mutate and kill 25 million people. She said to Jack that he was suited for the job because he didn't care. Hunt was present at the handover and received the vaccine information on the 456 radio frequency.
In 2009, the order to kill her was sent out as Bridget Spears was given a blank page by the Home Office in connection with the return of the 456. She was killed shortly after. (TV: Children of Earth: Day Two)