Since they can't get the real question from Arthur's brain, Benjy mouse and Frankie mouse try to come up with a fake question—something that sounds good when the answer is "42." They settle on "How many roads must a man walk down?" (See our Shout-Outs section if you don't know where that question is from.)
Meanwhile, Arthur and his friends are trying to escape when they discover why the alarms are going off.
It's the galactic police, who are trying to arrest Zaphod for stealing the Heart of Gold. Oh, yeah, now we remember that. It's been so long since anyone mentioned that Zaphod was wanted by the police that we almost forgot.
So two policemen start shooting at our heroes who take shelter behind a big computer. Well, "heroes" might be stretching things. Let's say "people we know." In any case, did we mention that these aren't ordinary policemen? As one of them comments, "we're a couple of intelligent caring guys that you'd probably quite like if you met us socially! I don't go around gratuitously shooting people and then bragging about it afterwards in seedy space-rangers bars, like some cops I could mention! I go around shooting people gratuitously and then I agonize about it afterwards for hours to my girlfriend!" (32.40).
But the cops keep shooting at these people we know, which is, as the British say, a bummer. Especially when the computer our gang is hiding behind starts melting.
(If you know the radio show and television version, things take a drastically different turn around here. If you've been trying to fake knowledge of the book by watching the movie, then you probably got lost after the credits rolled.)