At the beginning of the first issue, Casanova "Cass" Quinn works as a freelance thief and espionage artist who has turned his back on the rest of the Quinn family. His father, Cornelius, runs the world-spanning spy organization E.M.P.I.R.E. of which Casanova's twin sister Zephyr is a top agent, while his mother Anna has been hidden away in a vegetative state for unknown reasons. Casanova is the black sheep in the family and only makes contact with his father when his sister is killed during a mission - they meet again and fight at her funeral.