The "Hitchhiker's Guide to the Galaxy" is one of the most successful books in our Galaxy.
Ford Escort is an alien reporter for the book, stranded on Earth for the last 15 years.
Arthur Dent is an unaware earth inhabitant, a friend of Ford, entangled in his own minor earth problems.
But Arthur (and the rest of Earth inhabitants) suddenly becomes aware that they are not alone in the Galaxy. A Vogon fleet establishes communication. Unfortunately, this milestone in human history lasts only a few minutes. Earth is demolished by Vogons to make space for a brand new interstellar highway.
Arthur is the only earth inhabitant that survives. He is dragged into an interstellar hitchhiking by his friend Ford.
During his travels, he meets Trillian (another Earther that survived the demolition), Zaphod Beeblebrox (a playboy and President of the Galaxy) and Marvin (a paranoid android). And they discover that Earth was not randomly generated by forces of nature to just orbit the Sun, but had another greater purpose.
This is the first book of a five-book trilogy "The Hitchhiker's Guide to the Galaxy". A comedy space opera, and an acerbic satire of humanity, masterfully woven by Douglas Adams and elaborately narrated by Stephen Fry.