Barbara Gordon Hardy was an ex-thief who was determined to become a S.H.I.E.L.D. agent. Using her natural athletic skills to fight crime, she created a superheroic identity, the Black Bat. She quickly proved her worth to S.H.I.E.L.D. agent Bruce Wayne. Barbara was invited to join the secret organization.
Over a short period of time, Black Bat and Bruce Wayne became more than teammates, and soon fell in love. Bruce was planning on marrying her, when they were sent on a mission to stop a doomsday weapon. She and Bruce managed to destroy the weapon, but Bruce was lost in the explosion that followed. It is unknown if Bruce escaped, or if Black Bat managed to save the man she loved.
Black Cat and Batgirl were combined in a Marvel versus DC crossover.