The museum was not open, but Margont slipped one of the attendants a good tip to open it for him. Again, Margont was stupefied to see that Paris continued to live almost normally.

He began to walk through galleries of indescribable opulence. He wandered slowly, sometimes hurrying towards a work, then turning back to see another one. He was immersing himself in the labyrinth of art, freeing his mind of rigorous classifications and didactic organisation and allowing his subjectivity to direct him like Ariadne’s thread. Around him satyrs chased nymphs; he was disconcerted by the beauty of a Venus, aroused by the erotic pose of another; Eros sat astride a centaur; Diana received the allegiance of stags and does in a clearing; gladiators slaughtered each other; the draping of togas and robes was so realistic he fully expected to see their stone folds stirring in the breeze; a marble Cupid gently gathered up a butterfly; the paintings were exuberant with here an azure sky filled with cherubs, there a ferocious evocation of a medieval battle; there were the subtle contrasts of chiaroscuros and the seductive charms of Mademoiselle Caroline

Riviere painted by Ingres; the flamboyant depictions of Ancient Rome, bright with colour and movement, contrasted with the calm intimacy of the Three Graces, naked and taken by surprise by the unwelcome spectator. Margont was surrounded by Raphael, Rembrandt, Michelangelo, Rubens, Correggio, Veronese, Poussin, David, the Van Eyck brothers. He was drunk on beauty. Then he arrived in front of the Mona Lisa. Yes, if the world were about to be destroyed, he would be quite content to die contemplating that smile.

As he was roaming about in that fashion, he was struck by one particular work, an ancient mosaic imported from Italy. He had never heard of it, and its position in the museum, stuck in the corner of one of the galleries, indicated that Dominique Vivant De-non, the director of the museum and the mastermind behind this ‘Louvre of all the conquests’, knew little more. But what emotion! Margont was overcome by vertigo. The large mosaic fragment represented the face of a woman. Why did he find her so haunting? Her beauty upset him. He reflected that at that very moment, his friend Fernand was in the arms of his lover, whilst here he was with a two-thousand-year-old beauty made of pieces of coloured stone ... His thoughts darkened further. A Prussian cannonball might very well blow him to smithereens in a few hours, turning him into a mosaic of flesh ...

He still could not tear himself away from that face. He stretched out a hand and brushed her cheek; he was enraptured. The woman seemed to be trying to tell him something. His gaze moved from tessera to tessera, taking in the whole picture, then focusing on a single detail. Sometimes he saw a Roman beauty, sometimes all he saw were little fragments of colour. He was reminded of the investigation. Each clue and each of his deductions was like one of those tesserae. And piecing them together in the right order would reveal the whole picture in all its clarity. He had understood everything! Everything fitted, everything made sense! He kept repeating that to himself, but the woman seemed to be murmuring, ‘Not exactly ...’

He decided to embark on a sort of exercise. He would go once

more through all the elements of the inquiry, treating each like a piece of mosaic and building a complete solution.

As he did this, he was able to clear up a few little mysteries without it altering the overall picture. Varencourt had stolen documents about the defence of Paris from Colonel Berle’s house to confuse investigators about the motives for the murder. He hadn’t used curare to kill Berle, because he didn’t yet have any. He had procured it later, thanks to the contacts of the secret society and used it to kill Count Kevlokine in a sort of run-through before attempting to murder the Emperor with it. Varencourt had not imagined that the investigator would call on a doctor for help, still less that the doctor in question would be brilliant enough to be able to discover the true cause of death. People were supposed to assume that Kevlokine’s heart had not been able to stand the pain of the burns. Varencourt was extremely intelligent, but he did sometimes underestimate his enemies. None of this changed Margont’s initial conclusions.

But there were two little mysteries that did not fit. First, why did

Charles de Varencourt not burn Count Kevlokine’s face as he had burnt Colonel Berle’s? And secondly, why had he left the Swords of the King emblem on the second corpse, if his motivation was vengeance for the fire of Moscow? Margont was annoyed. The two details were like tesserae left over after he had completed the mosaic! He had been so happy, so proud that he had been able to unmask his adversaries. But now there were these two annoying grains of sand. He would almost have liked to sweep them under the carpet ...

A memory came to him. He loved to talk medicine with Jean-Quenin. One day he had asked him what, in his opinion, was the hardest thing to learn in his field. Margont had been prepared for anything - complicated anatomical drawings bristling with Latin terms, or exotic illness, pharmacology - except for the response he received. Jean-Quenin had said, The hardest thing is having the modesty and courage to reconsider a diagnosis.’ Now Margont finally understood what his friend had meant.

He remembered that Pinel had confirmed that the question of which part of the body had been burnt should not be overlooked. He mentally swept away the old mosaic and started again with the two surplus tesserae, which he placed in the middle of the new picture. But he was incapable of fitting the other elements round them.

The Roman lady continued to smile at him, relishing her unalterable beauty. Meanwhile, Margont now felt more fragmented than she was.

CHAPTER 42

ON 29 March, Napoleon rose at two in the morning. The French army set off on a frenzied march.

But it was not fast enough to worry the Allies, so the Emperor decided he needed to take more dramatic risks. He sent an advance guard of only a thousand cavalry commanded by General Guyot. The rest of the army would follow as quickly as possible. It was important for the French to show themselves, to appear with a great fanfare behind the enemy. Their only hope was to play on the fear that Napoleon inspired and to fool the enemy into thinking that he would suddenly materialise with all his troops.

That day Parisians were alarmed to watch Empress Marie-Louise and her son, the King of Rome, leaving Paris for Blois, escorted by two thousand soldiers.

The evening before, Joseph Bonaparte had convened the regency council to decide whether the Empress should leave or stay.

Talleyrand had proposed that the Empress and her son remain in Paris, and most of the council agreed. Marie-Louise herself wanted to stay. But Joseph produced a letter from Napoleon dated 6 March in which he ordered that his wife and son should be helped to leave Paris if the city were menaced. The order was intended to ensure that they would not fall into the hands of the enemy. Everyone agreed to obey Napoleon’s injunction, which also included a number of dignitaries, ministers and members of the Senate. Joseph hoped to lessen the impact of the Empress’s departure by having a proclamation posted all over Paris stating that he would be staying. But all that did was give rise to a little ditty:

Great Kingjoseph wan and pale

Stayed behind to save us all

But if this plan of his should fail

Rest assured he’ll save himself!

Marshals Marmont and Mortier arrived on the outskirts of the capital and immediately positioned their twelve thousand men to protect the city.