The Heart of Gold's crew is trapped on a spaceship heading toward a star. They can't control the ship and the teleporter is out of order. Ford Prefect is able to get it to work, but without a guidance system. They could literally be sent anywhere. Fortunately, Zaphod and Trillian are sent to the Heart of Gold, but Ford and Arthur are sent somewhere else entirely. They will make some startling discoveries before the end, while Zaphod and Trillian get to meet the man who secretly runs the universe.
Page count is significant to the plot of the book.