Whereas Modesty in the comic strip and novels was said to be of uncertain Eastern European ancestry (but adopted England as her homeland), and her companion Willie Garvin was a Cockney, the telefilm makes both characters American.
The plot, set in what appears to be Los Angeles, involves Modesty and Willie preventing the kidnap of a young girl who turns out to be a computer genius and has been working for Tarrant's agency.
Although both Modesty and Willie's back stories are given as described by O'Donnell, no explanation is provided for their North American accents or presence in California.
The American group Sparks wrote and recorded the theme song "Modesty Blaise" for the pilot.
After the cancellation of the proposed series, Sparks released the song in Europe under the amended title "Modesty Plays" in late 1982/early 1983.