Cardia, a young woman who harbors a deadly poison in her entire body, has lived her life confined in a mansion alone, feared by others as a monster.

Lupin and his companions have been using the mansion of a noble named Saint-Germain as their hideout. When Cardia meets Saint, he makes a comment that seems to carry a deeper, hidden meaning.

A phantom thief has been appearing all over London, stealing treasure only from vampires. As the case involves vampires, Van springs into action. Cardia wants to help as well, and they set out to capture this phantom thief.

Lupin and the rest move forward with the plan to capture the train Finis is riding. Lupin and Cardia board the train in disguise, and all seems to go as planned until a man appears before Lupin.

Thanks to Finis, Lupin and the others are on the wanted list after the train explosion, making their search for information on Isaac difficult. Fran shuts himself up in his lab, making Cardia worry.

A mafia-sponsored airship race is being held, and first prize is the posthumous writings of Isaac Beckford. Lupin and the others believe the writings might give them some clues about Isaac, so they enter the race.