HG: There are five books in all, three written as a trilogy and then two more added at seperate times later on. FOr some reason the TV series only covers the first two, although the third was released at the time I think? Or maybe not? As for what it's about... that's a bit tricky. Basically it's about a man who discovers his best friend is actually an alien when his friend rescues him moments before the earth is destroyed to make way for an interplanetary bypass route (they "hitch a ride" on one of the demolition fleet ships, hence the name). But I think the story is really just a setting for the author to excercise his brilliant wit and absurd views on life, the universe and everything (which incidently is the name of the third book in the series). I have read them all, plus one or two others by Adams, and I would thoroughly recommend at least reading the first one; if you don't like it, however, it's probably not worth bothering with the others.