"I think they're just strange symbols of some kind," said Zaphod, hardly glancing back.
Trillian shrugged and hurried after him.
From time to time a doorway led either to the left or right into smallish chambers which Ford discovered to be full of derelict computer equipment. He dragged Zaphod into one to have a look. Trillian followed.
"Look," said Ford, "you reckon this is Magrathea ..."
"Yeah," said Zaphod, "and we heard the voice, right?"
"OK, so I've bought the fact that it's Magrathea — for the moment. What you have so far said nothing about is how in the Galaxy you found it. You didn't just look it up in a star atlas, that's for sure."
"Research. Government archives. Detective work. Few lucky guesses. Easy."
"And then you stole the Heart of Gold to come and look for it with?"
"I stole it to look for a lot of things."
"A lot of things?" said Ford in surprise. "Like what?"
"I don't know."
"What?"
"I don't know what I'm looking for."
"Why not?"
"Because ... because ... I think it might be because if I knew I wouldn't be able to look for them."
"What, are you crazy?"
"It's a possibility I haven't ruled out yet," said Zaphod quietly. "I only know as much about myself as my mind can work out under its current conditions. And its current conditions are not good."
For a long time nobody said anything as Ford gazed at Zaphod with a mind suddenly full of worry.
"Listen old friend, if you want to ..." started Ford eventually.