Pontchartrain smiled. "Madame la duchesse, you would have me and Monsieur Rossignol believe that when two such ladies as you and the Countess are together in private, you have nothing better to do than talk about us?"

The Duchess was taken aback for a moment, then whooped. "Monsieur, you tease me!"

Eliza gave Rossignol an especially hard squeeze, and he shifted uneasily.

"So far, it does not seem to be happening, for Monsieur Rossignol is so quiet!" observed the Duchess in a rare faux pas; for she should have known that the way to make a quiet person join the conversation is not to point out that he is being quiet.

"Before you joined us, madame, he was telling me that he has been wrestling with a most difficult decypherment—a new code, the most difficult yet, that is being used by the Duke of Savoy to communicate with his confederates in the north. He is distracted—in another world."

"On the contrary," said Rossignol, "I am quite capable of talking, as long as you do not ask me to compute square roots in my head, or something."

"I don't know what that is but it sounds frightfully difficult!" exclaimed the Duchess.

"I'll not ask you to do any such thing, monsieur," said Pontchartrain, "but some day when you are not so engaged—perhaps at the Countess's salon—I should like to speak to you of what I do. You might know that Colbert, some years ago, paid the German savant Leibniz to build a machine that would do arithmetic. He was going to use this machine in the management of the King's finances. Leibniz delivered the machine eventually, but he had in the meantime become distracted by other problems, and now, of course, he serves at the court of Hanover, and so has become an enemy of France. But the precedent is noteworthy: putting mathematical genius to work in the realm of finance."

"Indeed, it is interesting," allowed Rossignol, "though the King keeps me very busy at cyphers."

"What sorts of problems did you have in mind, monsieur?" Eliza asked.

"What I am going to tell you is a secret, and should not leave this sleigh," Pontchartrain began.

"Fear not, monseigneur; is any thought more absurd than that one of us might be a foreign spy?" Rossignol asked, and was rewarded by the sensation of four sharp fingernails closing in around his scrotum.

"Oh, it is not foreign spies I am concerned about in this case, but domestic speculators," said the Count.

"Then it is even more safe; for I've nothing to speculate with," said Eliza.

"I am going to call in all of the gold and silver coins," said Pontchartrain.

"All of them? All of them in the entire country!?" exclaimed the Duchess.

"Indeed, my lady. We will mint new gold and silver louis, and exchange them for the old."

"Heavens! What is the point of doing it, then?"

"The new ones will be worth more, madame."

"You mean that they will contain more gold, or silver?" Eliza asked.

Pontchartrain gave her a patient smile. "No, mademoiselle. They will have precisely the same amount of gold or silver as the ones we use now—but they will be worth more, and so to obtain, say, nine louis d'or of the new coin, one will have to pay the Treasury ten of the old."

"How can you say that the same coin is now worth more?"

"How can we say that it is worth what it is now?" Pontchartrain threw up his hands as if to catch snowflakes. "The coins have a face value, fixed by royal decree. A new decree, a new value."

"I understand. But it sounds like a scheme to make something out of nothing—a perpetual motion machine. Somewhere, somehow, in some unfathomable way, it must have repercussions."

"Quite possibly," said Pontchartrain, "but I cannot make out where and how exactly. You must understand, the King has asked me to double his revenues to pay for the war. Double! The usual taxes and tariffs have already been squeezed dry. I must resort to novel measures."

"Now I understand why you would like the advice of France's greatest savants," said the Duchess. Whereupon all eyes turned to Rossignol. But he had suddenly braced his feet and jerked his head back. For a few moments he stared up at the indigo sky through half-closed eyes, and did not breathe; then he exhaled, and took in a deep draught of the cold air.

"I do believe Monsieur Rossignol has been seized by some sudden mathematical insight," said Pontchartrain in a hushed voice. "It is said that Descartes's great idea came to him in a sort of religious vision. I had been skeptical of it until this moment, for the very thought seemed blasphemous. But the look on Monsieur Rossignol's face, as he cracked that cypher, was unmistakably like that of a saint in a fresco as he is drawn, by the Holy Spirit, into an epiphanic rapture."

"Will we see a lot of this sort of thing, then, at the salon?" asked the Duchess, giving Rossignol a very dubious look.

"Only occasionally," Eliza assured her. "But perhaps we ought to change the subject, and give Monsieur Rossignol an opportunity to gather his wits. Let's talk about…horses!"

"Horses?"

"Those horses," said Eliza, nodding at the two that were drawing the sleigh.

She and Rossignol were facing forward. The Duchess and the Count had to turn around to see what she was looking at. Eliza took advantage of this to wipe her hand on Rossignol's drawers and withdraw it. Rossignol hitched up his breeches weakly.

"Do you fancy them?" asked the Duchess. "Louis-François is inordinately proud of his horses."

"Until now I had only seen them from a distance, and supposed that they were simply white horses. But they are more than that; they are albinos, are they not?"

"Ths distinction is lost on me," the Duchess admitted, "But that is what Louis-François calls them. When he comes back from the south he will be glad to tell you more than you wish to hear!"

"Are they commonly seen? Do many people have them here?" Eliza asked. But they were interrupted by, of all things, a man riding an albino horse: Étienne de Lavardac d'Arcachon, who had ridden out from the château to meet them. "I am mortified to break in on you this way," he said, after greeting each of them individually, in strict order of precedence (Duchess first, then Pontchartrain, Eliza, horses, mathematician, and driver), "but in your absence, Mother, I am the acting host of the party, and must do all in my power to please our guests—one of whom, by the way, happens to be his majesty the King of France—"

"Oooh! When did le Roi arrive?"

"Just after you left, Mother."

"Just my luck. What do his majesty and the other guests desire?"

"To see the masque. Which is ready to begin."

ONE END OF THE GRAND ballroom of La Dunette had been converted into the English Channel. Papier-mâché waves with plaster foam, mounted on eccentric bearings so that they cycled about in a more or less convincing churn, had been arranged in many parallel, independently moving ranks, marching toward the back of the room, and raked upwards so that any spectator on the ballroom floor could get a view of the entire width of the "Channel" from "Dunkerque" (a fortified silhouette downstage) to "Dover" (white cliffs and green fields upstage). To stage left was a little pen where a consort sawed away on viols. To stage right was a royal box where King Louis XIV of France sat on a golden chair, with the Marquise de Maintenon at his right hand, dressed more for a funeral than a Christmas party. A retinue was massed behind them. So close to the front of it that he could have put a hand on Maintenon's shoulder was Father Édouard de Gex—this a way of saying that there had better be no salacious bits. Not that Madame la duchesse d'Arcachon would ever even conceive of such a thing; but she had hired artists and comedians to produce it, and one never knew what such people would come up with.