At the beginning of the mazurka， Boris saw that a general of the staff， Balashov， one of the persons in closest attendance on the Tsar， went up to him， and， regardless of court etiquette， stopped close to him， while he conversed with a Polish lady. After saying a few words to the lady， the Tsar glanced inquiringly at Balashov， and apparently seeing that he was behaving like this only because he had weighty reasons for doing so， he gave the lady a slight nod and turned to Balashov. The Tsar’s countenance betrayed amazement， as soon as Balashov had begun to speak. He took Balashov’s arm and walked across the room with him， unconsciously clearing a space of three yards on each side of him as people hastily drew back. Boris noticed the excited face of Araktcheev as the Tsar walked up the room with Balashov. Araktcheev， looking from under his brows at the Tsar， and sniffing with his red nose， moved forward out of the crowd as though expecting the Tsar to apply to him. （Boris saw that Araktcheev envied Balashov and was displeased at any important news having reached the Tsar not through him.） But the Tsar and Balashov walked out by the door into the lighted garden， without noticing Araktcheev. Araktcheev， holding his sword and looking wrathfully about him， followed twenty paces behind them.
Boris went on performing the figures of the mazurka， but he was all the while fretted by wondering what the news could be that Balashov had brought， and in what way he could find it out before other people. In the figure in which he had to choose a lady， he whispered to Ellen that he wanted to choose Countess Pototsky， who had， he thought， gone out on to the balcony， and gliding over the parquet， he flew to the door that opened into the garden， and seeing the Tsar and Balashov coming into the verandah， he stood still there. The Tsar and Balashov moved towards the door. Boris， with a show of haste， as though he had not time to move away， squeezed respectfully up to the doorpost and bowed his head. The Tsar in the tone of a man resenting a personal insult was saying：
“To enter Russia with no declaration of war！ I will consent to conciliation only when not a single enemy under arms is left in my country，” he said.
It seemed to Boris that the Tsar liked uttering these words： he was pleased with the form in which he had expressed his feelings， but displeased at Boris overhearing them.
“Let nobody know of it！” the Tsar added， frowning.
Boris saw that this was aimed at him， and closing his eyes， inclined his head a little. The Tsar went back to the ballroom， and remained there another half hour.
Boris was the first person to learn the news that the French troops had crossed the Niemen； and， thanks to that fact， was enabled to prove to various persons of great consequence， that much that was hidden from others was commonly known to him， and was thereby enabled to rise even higher than before in the opinion of those persons.
The astounding news of the French having crossed the Niemen seemed particularly unexpected from coming after a month’s uninterrupted expectation of it， and arriving at a ball！ At the first moment of amazement and resentment on getting the news， Alexander hit on the declaration that has since become famous—a declaration which pleased him and fully expressed his feelings. On returning home after the ball at two o’clock in the night， the Tsar sent for his secretary， Shishkov， and told him to write a decree to the army and a rescript to Field-Marshal Prince Saltykov； and he insisted on the words being inserted that he would never make peace as long as one Frenchman under arms remained in Russia.
The next day the following letter was written to Napoleon：
MONSIEUR MON FRèRE，—I learnt yesterday that in spite of the loyalty with which I have kept my engagements with your Majesty， your troops have crossed the frontiers of Russia， and I have this moment received from Petersburg the note in which Count Lauriston informs me as cause of this invasion that your majesty considers us to be in hostile relations ever since Prince Kurakin asked for his passport. The causes on which the Duc de Bassano based his refusal to give these passports would never have led me to suppose that the action of my ambassador could serve as a ground for invasion. And， indeed， he received no authorisation from me in his action， as has been made known by him； and as soon as I heard of it I immediately expressed my displeasure to Prince Kurakin， commanding him to perform the duties entrusted to him as before. If your majesty is not inclined to shed the blood of your subjects for such a misunderstanding， and if you consent to withdraw your troops from Russian territory， I will pass over the whole incident unnoticed， and agreement between us will be possible. In the opposite case， I shall be forced to repel an invasion which has been in no way provoked on my side. Your Majesty has it in your power to preserve humanity from the disasters of another war.—I am， etc.，
（Signed） ALEXANDER.