Ford Prefect is an alien from Betelgeuse. He is a galactic traveler who takes as his guide the "Hitchhiker's Guide to the Galaxy," a book that contains information and advice for space travelers. He is stranded, along with Arthur Dent, on prehistoric Earth as the book opens. Using a sensor device called the "Sub-Etha Sens-O-Matic" he is able to detect warps in the fabric of time and space and travel through time. allowing him to escape his isolation on Earth along with Arthur.
Ford is mainly interested in having a good time and takes little interest in trying to save the universe or learn its secrets. He acts as a guide for Arthur, often explaining odd things about the universe that Arthur knows nothing about.
