Joseph Conrad's Heart of Darkness, now his most famous work, was first published in 1899 in serial form in London's Blackwood's Magazine, a popular journal of its day. The work was well received by a somewhat perplexed Victorian audience. It has since been called by many the best short novel written in English. At the time of its writing (1890), the Polish-born Conrad had become a naturalized British citizen, mastered the English language, served for ten years in the British merchant marines, achieved the rank of captain, and traveled to Asia, Australia, India, and Africa. Heart of Darkness is based on Conrad's firsthand experience of the Congo region of West Africa. Conrad was actually sent up the Congo River to an inner station to rescue a company agent-not named Kurtz but Georges-Antoine Klein-who died a few days later aboard ship. The story is told in the words of Charlie Marlow, a seaman, and filtered through the thoughts of an unidentified listening narrator. It is on one level about a voyage into the heart of the Belgian Congo, and on another about the Journey into the soul of man. In 1902, Heart of Darkness was published in a separate volume along with two other stories by Conrad. Many critics consider the book a literary bridge between the nineteenth and twentieth centuries and a forerunner both of modem literary techniques and approaches to the theme of the ambiguous nature of truth, evil, and morality. By presenting the reader with a clearly unreliable narrator whose interpretation of events is often open to question, Conrad forces the reader to take an active part in the story's construction and to see and feel its events for him—or herself.