"Monsieur," he said, unfolding his map of France, "I want to catch up some one who has carried off the woman I love and is making for Nantes by motor. The abduction took place at midnight. It is now about eight o'clock. Suppose that the motor, which is just a hired taxi with a driver who has no inducement to break his neck, does an average of twenty miles an hour, including stoppages—in twelve hours' time—that is to say, at twelve o'clock—our man will have covered two hundred and forty miles and reached a spot between Angers and Nantes, at this point on the map."
"Les Ponts-de-Drive," agreed Davanne, who was quietly listening.
"Very well. Suppose, on the other hand, that an aeroplane were to start from Issy-les-Moulineaux at eight o'clock in the morning and travel at the rate of sixty miles an hour, without stopping—in four hours' time—that is to say, at twelve o'clock—it would reach Les Ponts-de-Drive at the exact same moment as the motor. Am I right?"
"Perfectly."
"In that case, if we agree, all is well. Does your machine carry a passenger?"
"Sometimes she does."
"We'll start at once. What are your terms?"
"It depends. Who are you?"
"Arsène Lupin."
"The devil you are!" exclaimed Davanne, a little taken aback.