The Mysterious Diary tells the adventures of three children who, in a mysterious way, meet a peculiar caveman who will help them return to their home. The protagonists, will grow throughout the literary saga "The Guardians of Fantasy" at the same time that their readers, because it is only the first delivery and, as if it were a videogame, the child will delve into different stories linked to throughout the entire saga.

Through the app "Fantasy. The Guardians of Fantasy ", the reader will discover a series of clues that aim to make reading more attractive by participating in a great game of detectives. Through a series of clues that the app will show, we must solve the riddles that are proposed by scanning the text of the physical book and, once each mystery is solved, we will access the Easter eggs (additional multimedia content) that are hidden in the play.