Mia Connery serves as agent 009-7 within the Number Nine Group, an intelligence unit of the Western Bloc's Zero Zero Organization during a protracted Cold War. She reports directly to the group's leader, Number Zero, and undertakes missions alongside fellow agents Mylene Hoffman, Vanessa Ibert, and Berta Kastner. Her assignments often bring her into conflict with Eastern Bloc operatives.

Her defining capability stems from advanced cybernetic modifications: her entire skeleton, muscles, and skin consist of engineered biological tissue. This allows her to execute complete physical transformations beyond simple disguise, enabling her to alter her appearance, voice, and personality at will to mimic nearly any individual. This integrated bio-morphing ability is her signature skill.

While capable of emotional detachment during missions, Mia exhibits a playful personality outside operational contexts. She occasionally employs her abilities for pranks, such as impersonating a priest in the spaces above the team's covert meeting chambers, contrasting her focused and unsentimental professional demeanor during assignments.

Her earliest documented mission involved extracting Eastern Bloc defector Zond Soyuz, possessor of a powerful energy source sought by the Western Bloc. Infiltrating the stronghold of Soyuz's captor, Ivan Godunov, she penetrated his inner circle through disguise. Though the team failed to secure Soyuz, they recovered his invention, and Mia eliminated Godunov.

Within the Number Nine Group, her motif evokes the "Great Britain" character (007) from Cyborg 009, sharing similar espionage capabilities, reflected in her codename 009-7. She operates as part of an all-female team, maintaining consistent professional relationships with colleagues during joint missions for Western Bloc objectives.