In England, Lord Marquess hosts a party for railway enthusiasts on his vast estate which includes a replica railroad. Zenigata convinces NYPD's Inspector Queen that Lupin will be there to steal a valuable historic railway ticket, so he attends the party. Queen's nephews, Manfred Lee and Frederic Dannay, would-be detectives who are visiting from the United States, follow Fujko onto the Lord Marquess estate. Meanwhile, Morton, the Marquess' butler, kills the lord and pretends to be the Marquess...