Originally a 4-part play written by Maurice Leblanc and Francis de Croisset in 1908, it was subsequently novelized by Leblanc and published in 1909. First translated in English in 1909 by Edgar Jepson.
Chapters: 1. The Millionaire's Daughter 2. The Coming of the Charolais 3. Lupin's Way 4. The Duke Intervenes 5. A Letter from Lupin 6. Again the Charolais 7. The Theft of the Motor-Cars 8. The Duke Arrives 9. M. Formery Opens the Inquiry 10. Guerchard Assist 11. The Family Arrives 12. The Theft of the Pendant 13. Lupin Wires 14. Guerchard Picks up the True Scent 15. The Examination of Sonia 16. Victoire's Slip 17. Sonia's Escape 18. The Duke Stays 19. The Duke Goes 20. Lupin Comes Home 21. The Cutting of the Telephone Wires 22. The Bargain 23. The End of the Duel