Motifs in the James Bond film series the degree to which Bond girls are pivotal to propelling the plot forward varies from one film to the next. Five of the Bond girls are "bad" girls (or at least working for the villain) who turn "good" (or switch sides) usually due to Bond's influence. Bond has fallen in love with only Tracy di Vicenzo in "On Her Majesty's Secret Service" and Vesper Lynd in "Casino Royale", but both of them die at or near the end of the respective films. Roald Dahl, a screenwriter of "You Only Live Twice", said he was given a formula to work to
On Her Majesty's Secret Service (novel) Royale"'s Vesper Lynd, which he did every year. The emotional side continues with Bond asking Tracy to marry him. The character of Tracy is not as well defined as some other female leads in the Bond canon, but Benson points out that it may be the enigmatic quality that Bond falls in love with. Benson also notes that Fleming gives relatively little information about the character, only how Bond reacts to her. Academic Christoph Lindner identifies the character of Marc-Ange Draco as an example of those characters who have morals closer to those of the traditional villains, but who act