The books get more serious in tone as the trilogy moves on. The Restaurant at the End of the Universe (1980) still broadly follows the plot of the Radio and TV series.

Life, the Universe and Everything (1982) concerns itself with Cricket, and a creature with a grudge called Agrajag. In So Long, and Thanks for All the Fish (1984) the girl in the cafe in Rickmansworth comes into her own, and Arthur returns to what might be the earth, and falls in love.

The final book Mostly Harmless (1992) comes full circle, with Arthur making sandwiches; discovering his daughter, Random; a new edition of the Guide; and the destruction of the Earth, again.