The Hitchhikers Guide to the Galaxy

Chapter 4:

Slartibartfast tells Arthur than mice are set up on earth as an experiment in behavioral psychology of them. They wanted to see how much humans have learned by observing the experiments they are doing on them.
But still there is Deep Thought, a supercomputer that can tell future probabilities and knows the answer to life and the universe. On a tape recorder the men listen to him speaking to the representatives of a philosophers union. Deep Thought declares that the answer to the ultimate question of life is 42, but that they would have to find the question which the computer that comes after him could tell them: The earth. Five minutes before the program was completed the Vogons had destroyed it!
They all go to the reception area and find Ford, Zaphod and Trillian lying bleeding in a subterranean corridor who say that they have been attacked by their hosts. The all meet the Frankie mouse and Benjy Mouse, 2 of the mice that control a large sector of the universe and tell slartibartfast that the earth does not need to be rebuilt anymore and that they are still looking for the ultimate question of time since a lot of money is given to them for the search by TV companies. The mice tell Arthur that for him and "Earth Girl" it will be easy to find the question of life and that it will make them very rich. The mice escape when police comes near but tell them to find the question of live. The coops shoot at them because they want to get their spaceship back. As they go on shooting the men realize that they wont be safe for a lot longer since the computer that is protecting them is about to blow up!