was clearly sexual, as evidenced by his letters to her (only discovered in 1957). Much later, they lived together, perhaps platonically, and remained together until Voltaire's death. Meanwhile, the Marquise also took a lover, the Marquis de Saint-Lambert. Prussia After the death of the Marquise in childbirth in September 1749, Voltaire briefly returned to Paris and in mid-1750 moved to Prussia at the invitation of Frederick the Great. The Prussian king (with the permission of Louis XV) made him a chamberlain in his household, appointed him to the Order of Merit, and gave him a salary of 20,000 French livres a year. He had rooms at Sanssouci and Charlottenburg Palace. Life went well for Voltaire at first, and in 1751 he completed Micromégas, a piece of science fiction involving ambassadors from another planet witnessing the follies of humankind. However, his relationship with Frederick began to deteriorate after he was accused of theft and forgery by a Jewish financier, Abraham Hirschel, who had invested in Saxon government bonds on behalf of Voltaire at a time when Frederick was involved in sensitive diplomatic negotiations with Saxony. He encountered other difficulties: an argument with Maupertuis, the president of the Berlin Academy of Science and a former rival for Émilie's affections, provoked Voltaire's Diatribe du docteur Akakia ("Diatribe of Doctor Akakia"), which satirized some of Maupertuis's theories and his persecutions of a mutual acquaintance, Johann Samuel König. This greatly angered Frederick, who ordered all copies of the document burned. On 1 January 1752, Voltaire offered to resign as chamberlain and return his insignia of the Order of Merit; at first, Frederick refused until eventually permitting Voltaire to leave in March. On a slow journey back to France, Voltaire stayed at Leipzig and Gotha for a month each, and Kassel for two weeks, arriving at Frankfurt on 31 May. The following morning, he was detained at an inn by Frederick's agents, who held him in the city for over three weeks while Voltaire and Frederick argued by letter over the return of a satirical book of poetry Frederick had lent to Voltaire. Marie Louise joined him on 9 June. She and her uncle only left Frankfurt in July after she had defended herself from the unwanted advances of one of Frederick's agents, and Voltaire's luggage had been ransacked and valuable items taken. Voltaire's attempts to vilify Frederick for his agents' actions at Frankfurt were largely