Berenyi

 was a Time Lord graduate of the Academy in bio-chronology, who had left Gallifrey to become a Designer. As a mercenary hired by wealthy clients to alter time, her work on "an assassination in a theatre in 1865" had attracted the attention of an unknown German from the 22nd century. This German hired her to go back to 1963 and "design" the assassination of John F. Kennedy. In this effort, she programmed a human male — who had been the chairman of the Fair Play For Cuba committee and who had a Russian wife — to shoot the president. As a part of her "design", she had established that Jack Ruby would kill the president's assassin.

A red-headed smoker at the time of the Kennedy assassination, was also given to wearing exclamation points, perhaps indicating that she had knowledge of the Doctor's affinity for wearing question marks. Like the Doctor, she possessed a fairly detailed knowledge of Earth culture and history. She seemed well-versed in the pop culture of the 1980s, and was known to like The Jesus and Mary Chain, Sonic Youth, Cherry 7UP and Arthur Miller's biography.

She was also known to have her own TARDIS. It presumably had a working chameleon circuit, since it was disguised as a filing cabinet in the book depository from which Kennedy's assassin operated. (BE: Untitled)