Arthur Dent, a man who "never could get the hang of Thursdays," had both his house and his planet demolished on one such Thursday. He, being the only survivor of Earth, was whisked off of the doomed planet moments before it's destruction by his actor friend, Ford Prefect, who was really from somewhere in the vicinity of Betelgeuse. They stow away on a Vogon Construction Fleet ship. They are thrown off of the ship in the middle of space, and picked up (most improbably) by Zaphod Beeblebrox, figurehead president of the galaxy, in the stolen ship Heart of Gold, with an infinite improbability drive. They eventually run in to several powerful beings from another dimension, who in this dimension appear to be mice. These mice happen to be after Arthur's brain for reasons that won't be mentioned here. When you are reading, keep one number in mind: 42.