Buried deep in a labyrinth of tunnels and caves under the Mediterranean Sea rests an invaluable object said to be linked to Christopher Columbus. The relic, an ornate egg, is the source of a unique and powerful energy, promising great wealth to the finder. Always eager for a challenge, Lupin heads out to find it with pals Goemon, Fujiko and Jigen, plus rival treasure hunter Rosalia. Of course the task is anything but simple. A pack of thugs sporting a heavily armed submarine is after the same egg, with the intention of using its energy to cause catastrophic changes to the Earth's weather systems. And to further complicate matters, Rosalia is struck with the revelation that the chief thug is her own father.