The Whale of Babylon

"One night, a thief breaks into the laboratory of Dr. Immanuel Margolis, who is persistently trying to end all the heartaches of humanity, and steals a medicine meant to treat his wife, who is a patient in a psychiatric hospital. Siblings Jonathan and Ella Margolis follow the thief and find themselves in the world of Babylon, a magical kingdom where sorcery and science, demons and machines, intermingle.

In a bold, original work of epic fantasy, which borrows motifs from Jewish, Babylonian, Sumerian and Accadian mythology and distills them into a new and exciting universe, Hagar Yanai tells the story of Jonathan and Ella, of the rebel Hillel ben-Shachar and of the heiress Nin-Urmuz, in their war for freedom, humanity and self-determination."

Text from the back cover. Impromptu translation by me. The book hasn't been translated into English, or any other language... yet. It should be, though.