‘But how can he be mentally disturbed when he kills if he is perfectly sane when he is planning the crime? We know that he did some research, drew up a plan, stole a servant’s outfit …’

‘How should I know? I’m not a specialist in these disorders.’

‘If I may be so bold, neither are the Polish investigators. I assume that one of them has been questioned.’

‘Of course not, because the culprit has confessed.’

‘How was this man tracked down?’

‘He had already committed a public order offence in the past. So the investigators questioned him, as they do all the usual suspects.’

Margont was furious. So much for the ideals of the Revolution and the rights of man! Were all men equal then, except the insane?

‘I see. “Insane and therefore suspect.” Or even better: “Insane and therefore guilty.”’

‘He confessed! And no force was used to make him confess. I’d sent one of my aides-de-camp to make certain of that.’

‘May I talk to this aide-de-camp?’

‘Yes, but after the campaign is over because he stayed behind in Poland to follow the trial.’

They were going round in circles but Margont remained unruffled.

‘How did the suspect confess, Your Highness? Did he give his own version of events or did he accept the one presented to him?’

The prince seemed exasperated by this conversation but was unable to bring it to an end.

‘Well, the facts were put to him and he admitted to them. It was quicker that way because he seemed incoherent. According to the report I was given of his interrogation, his explanations were hopelessly confused. For example, he would break off in the middle of a sentence and remain silent for several minutes, for no apparent reason, before continuing to talk but about something completely different in the same rambling manner. And he didn’t even seem to be aware of these inconsistencies.’

‘What are we to think of a confused mind that carries out a consistent plan in masterly fashion? Did he even understand what he had been made to confess to? I don’t doubt that he admitted to doing it. What’s surprising is that he didn’t also admit to being responsible for the double murder on the Lyons mail-coach, Marat’s assassination, the booby trap that almost blew up the Emperor in Rue Nicaise, and to being the man in the iron mask.’

‘Don’t overdo it. I don’t need you for that. At least I asked that, in view of his mental disorder, he should not be sentenced to death. That’s something.’

So they even wanted to execute him, did they? Margont felt nauseated.

‘I’m going to order a new inquiry,’ continued the prince. ‘I admit that your argument does trouble me. However, I’ve often had positive reports about the efficiency of the Polish authorities.’

Margont did not doubt that. He sensed a presence behind those who had conducted this mockery of an investigation. Countess Nergiss. The prince was so eager for this case to be solved … Bribing one of her servants and one or two Polish notables was neither here nor there in terms of expense as far as she was concerned. Margont had mixed feelings about this woman. Either she had been seduced by power or else she had acted out of love, to fulfil her husband’s dream. If that was the case, her ambition was rather moving and Margont could not bring himself to dislike her.

‘Nevertheless, it has to be him,’ muttered Eugène.

‘How did events that evening unfold?’

‘The murderer mingled with the guests. That must have been the case because there were sentries all around the castle and such a large number of people present …’

Of course he mingled with the guests because he was one of them! Margont exclaimed to himself. Still, at least the prince was co-operating now.

‘He went into the dressing room …’

‘How did he find it?’

‘Just after the performance a crowd of spectators hurried into the dressing rooms to congratulate the actors as they were removing their make-up. I went in myself. It was easy therefore to locate the place. The actors then went back out into the grounds. Mademoiselle Lasquenet returned to her dressing room later so her murderer then took an enormous risk in following her there because an admirer might have tried his luck with her, or a servant might have encountered him or heard him. He acted very swiftly, otherwise someone would certainly have caught him in the act. He entered the room. Mademoiselle Lasquenet was not worried. All she needed to do was to shout and a servant would hear her. Besides, either the murderer was disguised as a valet and she thought he had been sent by the countess, or he introduced himself as one of the guests. If that were the case, actresses are used to this sort of situation and know how to deal with people tactfully. The man took her by surprise and stabbed her twice. She died before she even had time to scream. So, as you can see, this crime is different from the one involving the Polish woman.’

‘But it’s very similar to the one involving the sentry – killing someone outright by stabbing them only twice. Besides, we can’t say whether the murderer would have mutilated his victim or not if he’d had time.’

‘On that subject, there is one detail. The murderer cut out her tongue.’

Margont shuddered. He could never get used to horror. ‘The tongue …’ Now it was his turn to feel unsettled. Fortunately, he had shaken the prince sufficiently to persuade him to provide all the details.

‘I’ve thought about it long and hard. An anecdote can perhaps explain such a cruel act. By the end of the performance, the audience was completely enthralled. Seeing this, Countess Nergiss suggested that the actors should give a repeat performance of certain scenes according to public request. Everyone joined in the spirit. They were even asked to recite speeches from other plays and were then applauded enthusiastically. From time to time someone asked a question. How could such and such an actor play such an odious character? Did they themselves feel anger when their character was angry? Opinions differed. Some of the actors maintained that you had to use your sensitivity and your emotions to “become” your character in order to perform the role properly. Hence a considerable limitation of roles because any given person could not “become” just anyone. Others thought that the actor remained an actor pretending to be the character. Therefore he had to use first and foremost his intelligence. Hence the possibility for a gifted actor to take on any role. In a word it was the insoluble debate begun by Monsieur Diderot.

‘Mademoiselle Lasquenet favoured the second point of view and proclaimed that she could play absolutely any role. Another actress, whose only fault was to be less beautiful and less talented than her stage partner, jealous of being eclipsed, challenged her to play a whore. How childish it was! They were no longer two young women but two adolescent girls ready to pull each other’s hair out. Mademoiselle Lasquenet gave a very convincing demonstration and even went as far as to caress her breasts. At that moment, the real spectacle was not what was happening on stage but on Countess Nergiss’s face. Mademoiselle Lasquenet continued in her role, this time using her tongue. She ran it over her lips quite indecently … The countess suddenly rose to her feet to applaud and the audience did likewise whilst Mademoiselle Lasquenet, whose cheeks were bright red, bowed politely, still surprised by her own boldness. That was what must have infuriated the murderer and driven him to take such risks. That’s why he cut out her tongue. Such cruelty unleashed by the shamelessness of a susceptible adolescent girl!’

The silence that ensued made the two men ill at ease.

‘Your Highness, General Triaire must provide me with an exact list of guests.’

‘Exact, exact … He’ll note down the names of those he saw.’

‘Can he try to establish who was absent at the time of the murder?’