A mad oath! An absurd and illogical war! What can he do, a single, unarmed stripling, against that phenomenon of energy and strength? On which side is he to attack him? He is unassailable. Where to wound him? He is invulnerable. Where to get at him? He is inaccessible.
Four o’clock in the morning. Isidore has again accepted his schoolfellow’s hospitality. Standing before the chimney in his bedroom, with his elbows flat on the mantel-shelf and his two fists under his chin, he stares at his image in the looking-glass. He is not crying now, he can shed no more tears, nor fling himself about on his bed, nor give way to despair, as he has been doing for the last two hours and more. He wants to think, to think and understand.
And he does not remove his eyes from those same eyes reflected in the glass, as though he hoped to double his powers of thought by contemplating his pensive image, as though he hoped to find at the back of that mirrored Beautrelet the unsolvable solution of what he does not find within himself.
He stands thus until six o’clock, and, little by little, the question presents itself to his mind with the strictness of an equation, bare and dry and cleared of all the details that complicate and obscure it.
Yes, he has made a mistake. Yes, his reading of the document is all wrong. The word aiguille does not point to the castle on the Creuse. Also, the word demoiselles cannot be applied to Raymonde de Saint-Véran and her cousin, because the text of the document dates back for centuries.
Therefore, all must be done over again, from the beginning.
How?
One piece of evidence alone would be incontestible: the book published under Louis XIV. Now of those hundred copies printed by the person who was presumed to be the Man with the Iron Mask only two escaped the flames. One was purloined by the captain of the guards and lost. The other was kept by Louis XIV., handed down to Louis XV., and burnt by Louis XVI. But a copy of the essential page, the page containing the solution of the problem, or at least a cryptographic solution, was conveyed to Marie Antoinette, who slipped it into the binding of her book of hours. What has become of this paper? Is it the one which Beautrelet has held in his hands and which Lupin recovered from him through Brédoux, the magistrate’s clerk? Or is it still in Marie Antoinette’s book of hours? And the question resolves itself into this: what has become of the Queen’s book of hours?
After taking a short rest, Beautrelet consulted his friend’s father, an old and experienced collector, who was often called upon officially to give an expert opinion and who had quite lately been invited to advise the director of one of our museums on the drawing up of the catalogue.
“Marie Antoinette’s book of hours?” he exclaimed. “Why, the Queen left it to her waiting-woman, with secret instructions to forward it to Count Fersen. After being piously preserved in the count’s family, it has been, for the last five years, in a glass case—”