The Tsar stopped Rouletabille in his enthusiastic outburst.

“All that would be very beautiful and perhaps admirable,” said he, more and more coldly, because he had entirely recovered himself,” if Natacha had not, herself, with her own hand, poisoned her father and her step-mother! — always with arsenate of soda.”

“Oh, some of that had been left in the house,” replied Rouletabille.  “They had not given me all of it for the analysis after the first attempt.  But Natacha is innocent of that, Sire.  I swear it to you.  As true as that I have certainly escaped being hanged.”

“How, hanged?”

“Oh, it has not amounted to much now, Your Majesty.”

And Rouletabille recounted his sinister adventure, up to the moment of his death, or, rather, up to the moment when he had believed he was going to die.

The Emperor listened to the young reporter with complete stupefaction.  He murmured, “Poor lad!” then, suddenly: 

“But how have you managed to escape them?”

“Sire they have given me twenty-four hours for you to set Natacha at liberty, that is to say, that you restore her to her rights, all her rights, and she be always the recognized heiress of Trebassof.  Do you understand me, Sire?

“I will understand you, perhaps, when you have explained to me how Natacha has not poisoned her father and step-mother.”

“There are some things so simple, Sire, that one is able to think of them only with a rope around one’s neck.  But let us reason it out.  We have here four persons, two of whom have been poisoned and the other two with them have not been.  Now, it is certain that, of the four persons, the general has not wished to poison himself, that his wife has not wished to poison the general, and that, as for me, I have not wished to poison anybody.  That, if we are absolutely sure of it, leaves as the poisoner only Natacha.  That is so certain, so inevitable, that there is only one case, one alone, where, in such conditions, Natacha would not be regarded as the poisoner.”

“I confess that, logically, I do not see,” said the Tsar, “anything beyond that but more and more of a tangle.  What is it?”

“Logically, the only case would be that where no one had been poisoned, that is to say, where no one had taken any poison.”

“But the presence of the poison has been established!” cried the Emperor.

“Still, the presence of the poison proves only its presence, not the crime.  Both poison and ipecac were found in the stomach expulsions.  From which a crime has been concluded.  What state of affairs was necessary for there to have been no crime?  Simply that the poison should have appeared in the expulsions after the ipecac.  Then there would have been no poisoning, but everyone would believe there had been.  And, for that, someone would have poured the poison into the expulsions.”

The Tsar never quitted Rouletabille’s eyes.