chunk: When Isidore Beautrelet discovers the Château de l'Aiguille in the department of Creuse, he thinks that he has found the solution to the riddle ("l'Aiguille Creuse" being French for "The Hollow Needle", and also the French title of the novel). However, he did not realize that the château was built by Louis XIV, the king of France, to put people off the track of a needle in Normandy, near the town of Le Havre, where Arsène Lupin, known also under the name of Louis Valméras, has hidden himself.