After a harrowing encounter with pirates at sea, Elisha Ringel travels to Vienna for the wedding of Mendele Strasbourg, the son of his good friend Rav Shloime Strasbourg, the rabbi of Pulichev. He finds the Jewish community prosperous, joyous and proud of its progress to preeminence in the Jewish world. But calamity looms on the horizon. The Queen of Spain has sent an urgent demand to the Emperor and Empress that they expel all the Jews from Vienna.
Exhilaration turns to desperation. How could such a barbarous thing happen in an age of reason and enlightenment? What could be done to prevent it? Would the prospect of a large payment into the royal coffers be sufficient? Could influence be brought to avert the evil decree? Would the support of other powerful monarchs be effective? And if so, how could it be obtained? A secret envoy would have to be sent to the foreign royal courts, but who should be chosen? Moreover, a group of vicious mercenaries lurks in the shadows, determined to go to any length to thwart the efforts of the community. Who hired these killers? What is their motivation?
In the end, Elisha is persuaded to accept the mission. His perilous journey takes him to Berlin, Hamburg and Venice as he frantically tries to escape the ambushes of his bloodthirsty pursuers. The fate of the Jews of Vienna hangs in the balance.
Envoy from Vienna is a work of historical fiction, but the trajectory of the story follows actual historical events. The book is set against the background of shifting political alliances that play an important part in the situation. The book also introduces Rav Gershon Ashkenazi, Chief Rabbi of Austria, the author of Shaalos Uteshuvos Avodas Hagershuni, one of the greatest Torah scholars of his generation.