Arsène Lupin III, grandson of the legendary gentleman thief Arsène Lupin, is a member of the international thieves' guild "The Works", which specializes in stealing valuable objects from wealthy owners. Lupin beats his fellow Works members Fujiko Mine (his would-be lover), Pierre (a computer genius) and Jiro to the theft of an ancient Ancient Olympic Games medal in Singapore, but is forced to surrender it to his rival, Michael Lee, when he threatens to kill him and Fujiko. At a meeting of The Works, Fujiko is hailed as the culprit behind the theft (thanks to her machinations), and Thomas Dawson, the leader of the organization and Lupin's mentor, shows them the most valuable item in The Works' possession - the Crimson Heart of Cleopatra, a necklace commissioned by Mark Antony to symbolize his love for the Queen of the Nile. However, a ruby of Cleopatra's intended to complete the necklace is missing. A trio of thugs led by Michael - Royal, Saber and Maria - steal the necklace and kill Jiro and Dawson, apparently in revenge for "Edward Lam", resulting in the disbanding of The Works. Devastated by Dawson's murder, Lupin, Fujiko, Pierre and Daisuke Jigen join forces to find Michael and the necklace.