"El libertino invisible" is a novel by Spanish author Benito Pérez Galdós, published in 1876. The book is part of Galdós' "Episodios nacionales" series, which consists of 46 novels that explore Spanish history and society during the 19th century.
: The story is described as a "very British" tale that blends elements of naturalism, science fiction, and the fantastic el libertino invisible libro pdf