When The Mysterious Stranger first appeared in English in Chambers’s Repository for February 1854, it had no author credit and remained anonymous until 2013. The English translation is actually an abridged version of the original German novella Der Fremde by Karl von Wachsmann. Other changes were moving the setting to the “Carpathians Mountains”. In the original German it seems it was set in “the Carniolan mountains” in present-day Slovenia.

The story follows a group of travelers in Austria who take refuge from wolves in a haunted castle called Castle Klatka. They are rescued by a mysterious stranger named Azzo von Klatka who lives in the castle ruins. One of the travelers, Franziska, begins to fall ill with the same symptoms as vampire victims, suggesting Azzo may be a vampire. The story has been pointed to be one of the influences to Dracula.