After fending off a series of skilled assassins, gentleman thief Lupin III and his band of allies follow a strange invitation to an uncharted island. When their plane is shot down, the gang is stranded and soon hunted by the island’s inhabitants, past enemies, and a monstrous immortal being known as Muom, who threatens to destroy Lupin's legacy. As a deadly toxic fog settles over them, Lupin must confront his greatest enemy in his most daring escapade yet.