Butterfly is one of Project Delta's deep cover agents, no birth certificate, no social security number, a complete ghost. When her cover is blown and she is set up for a murder she did not commit, she is unknowingly led to her father's doorstep, a man she thought died 20 years ago. Codenamed Nightingale, her father was once a member of the very same Project Delta, a spy in the violent aftermath of the Cold War, and believes they are behind her set-up. Trained to trust nothing and no one, Butterfly must decide whether to seek answers with the Project, or believe the man who betrayed her years ago.