Between science fiction and fantasy it is an exciting adventure towards unknown and alternative worlds, whether in the past, present or future. In this book, Cristián Londoño Proaño offers an exploration of various themes in these genres. He has distinguished himself for his extensive knowledge on the subject, which allows him to provide specialized information with great references such as Asimov, Heinlein, Bradbury, among others. He shares his reflections on science fiction and fantasy, instructs us in the history of science fiction and addresses the relationship between science fiction literature and cinema. Thanks to his experience in writing, he provides useful advice for writing stories in these genres.