From Baghdad, Kara Ben Nemsi and Hadji Halef Omar continue their journey to the banks of the Euphrates. They follow the trail of a secret society, explore the mysteries of the "Death Caravan," and become involved in thrilling events at the Tower of Babel. Ultimately, they have a surprising reunion with the wise Marah Durimeh. This narrative is set in the mid-1870s. It is a continuation of Volume 26, "The Lion of Blood Revenge." Volumes 28, "In the Realm of the Silver Lion," and 29, "The Petrified Prayer," partially continue the story but also serve as an autobiographical key novel, inspired by May's impressions from his great journey to the Orient in 1899/1900. The original title of this formerly four-volume travel narrative was "In the Realm of the Silver Lion I-IV." The title is also available as an e-book.