Von Kleist had taken the oath, and kept it faithfully.  But there is a wise Persian proverb which says:  “If you would change an obedient and submissive wife into a proud rebel, you have only to forbid something!  If you wish to keep a secret from the wife of your bosom, slay yourself, or tear out your tongue; if you live, she will discover your secret, even though hidden in the bottom of your heart.”  Louise von Kleist had proved the truth of this proverb.  She had discovered the secret which her husband wished to conceal from her.  She had soon recovered from the fleeting love entertained at first for the husband chosen for her by the king.  She had returned to the levity of her earlier days, and only waited for an opportunity to revenge herself upon her husband.  Louise hated him because he had never been rich enough to gratify her extravagant taste and caprices.  He had even restrained her in the use of her own means:  they were always in want of money, and constantly railing bitterly at each other.

For all this misery Louise wished to revenge herself upon her husband, as beautiful and coquettish women always wish to revenge themselves.  She was more than ready to believe the words of that poet who says that “a woman’s heart is always girlish and youthful enough for a new love.”  She wished to take special vengeance upon her husband for daring to keep a secret from her.  So soon as she discovered the object of these secret meetings, she informed the king, and implored him to come to her assistance and rescue her husband from those crooked paths which had cost her her wedded happiness and her fortune.  Frederick agreed at once to her proposition, not so much for her sake as because he rejoiced in the opportunity to free Fredersdorf from the mystic suppositions which had clouded his intellect, and convince him of the cunning and hypocrisy of the alchemist Pfannenschmidt.

Every necessary preparation had been made by order of the king.  The pious assembly had scarcely met, when Louise called the four policemen who were waiting in a neighboring house, and placed them in a small closet adjoining the ball-room, where every thing which took place could be both seen and heard.

The conspirators had no suspicion.  The meeting was larger than ever before.  There were people of all classes, from the day laborer to the comfortable burgher, from the honorable officer under government to the highest noble.  They prayed earnestly and fervently, and sang hymns to the honor and glory of God.  Then one of the popular priests stepped into the pulpit and thundered forth one of those arrogant, narrow-minded, and violent discourses which the believers of those days indulged in.  He declared all those lost, condemned to eternal torture, who did not believe as he believed; and all those elected and sanctified who adhered to his holy faith, and who, despising the command of the heretical king, met together for these forbidden services.