In Lupin Lupin III, the legendary gentleman thief’s grandson, the world of high-stakes crime revolves around the international guild known as The Works, a group that specializes in stealing priceless treasures from the ultra-wealthy. Early on, the young mastermind pulls ahead of his fellow members Fujiko Mine, Pierre, and Jiro to claim an ancient Olympic medal in Singapore, but is forced to surrender it to his rival Michael Lee when the latter menaces him and Fujiko.
At a Works gathering, Fujiko is celebrated as the prime suspect behind the medal theft, thanks to her calculated scheming, while Thomas Dawson, the organization’s leader and Lupin’s mentor, unveils the prize the guild guards: the Crimson Heart of Cleopatra, a necklace commissioned by Mark Antony to symbolize love for the Queen of the Nile. Yet the necklace is incomplete—a ruby is missing—setting off a chain of betrayals. A trio of thugs led by Michael—Royal, Saber, and Maria—steal the necklace and kill Jiro and Dawson, an act framed as revenge for the supposed betrayal of an earlier ally, Edward Lam, and this brutal strike leads to the disbanding of The Works. Grief-stricken by Dawson’s death, Lupin, Fujiko, Pierre, and Daisuke Jigen band together to recover the necklace and the ruby.
A year passes, and Lupin and Jigen have sharpened their thieving skills, but Jigen grows tired of Fujiko’s false leads. When Lupin is tipped off about trouble in Thailand, he is turned in to the police there and crosses paths with Interpol Inspector Koichi Zenigata. Zenigata reveals that Michael—now using the alias Georgio Zhang—is plotting a major auction with Momrachiao Pramuk, a Thai crime lord and the chairman of Navarone Security. The officer proposes a risky deal: Lupin should steal items that both he and the criminals intend to barter, so the police can arrest them and erase Lupin’s criminal record in the process. Reluctantly, Lupin agrees and enlists Goemon Ishikawa XIII into the crew.
As the players circle the chessboard, Fujiko meets with Michael, who explains that Edward Lam was a father figure to both of them and that Dawson’s betrayal in Egypt led to the loss of the Crimson Heart’s ruby. Pramuk is revealed as the thief who stole that ruby, and Michael resolves to purchase it to complete the necklace. Lupin, ever vigilant, uses lip-reading technology to listen in on Michael and Pramuk’s exchange and quietly declares that he will steal the necklace no matter who wins.
Disheartened by the turn of events, Michael offers to join Lupin’s team to reclaim the Crimson Heart and ruby from Pramuk’s fortress, the Ark, and Lupin accepts. The plan unfolds as Lupin and Michael infiltrate the Ark disguised as Zenigata and Narong, while Goemon, Jigen, and Fujiko breach the Ark’s defenses. Pierre and Joseph assist from the shadows, aided by Goemon’s prior research, as they reach the vault that holds the Crimson Heart. Pramuk traps the pair inside, intending to suffocate them, but Michael helps Lupin escape by placing him in the vault’s safe and detonating the door, sacrificing himself to save Lupin.
Pramuk hands Lupin and the others over to Zenigata and Narong, only to be arrested himself when the authorities use the Crimson Heart as evidence. Zenigata discovers too late that the necklace and ruby Lupin gave him are fakes. The pursuit continues as Lupin later tries to persuade Fujiko to wear the Crimson Heart, but she escapes with the necklace. In an epilogue of their endless chase, Lupin and Jigen slip away in their Fiat 500, leaving Zenigata to resume the chase once more.
